So in many games you have regions that are bordered on all sides by impassible geography of some sort or another. This has always bothered me as necessary but also acts as a reminder to pull you out of the fantasy.

I am looking for some real world examples of geography that could fit the bill and be used as a model.

  • Area should be 10 miles by 10 miles, though shape is irrelevant, just need the space.
  • The area should have no more than 2 or 3 access points. These access points should be usable by the average medieval person. Obviously a small group of trained individuals can access from virtually any direction, those don't matter
  • Biome type is not particularly relevant, though my preference is that it include forest.
  • 14
    $\begingroup$ Islands are pretty insular. Each island of Hawaii, for example. Or Gilligan's Island. But ... I think you mean "surrounded by physical land", rather than isolated because of ocean. Just wanted to throw it out there! $\endgroup$ – BrettFromLA May 17 '17 at 0:01
  • 2
    $\begingroup$ Who exactly do you want to contain? What technology and resources do they have which could help them to pass natural borders? And how long do you want to contain them? For their entire life or only for a few days until the Hunger Games are over? $\endgroup$ – Philipp May 18 '17 at 12:28
  • 1
    $\begingroup$ Pity you want a real world example else I'd have recommended a mobius strip :D $\endgroup$ – Carel May 18 '17 at 15:15
  • $\begingroup$ @James OK, I overread "Medieval". But what about the timescale? A medieval person might not be able to swim across a larger river, but they could definitely build a boat when they have a few weeks. $\endgroup$ – Philipp May 18 '17 at 16:52
  • 1
    $\begingroup$ Not really a solution for you, but a related idea I like is a small spherical planet. After walking for a while, you arrive to the place you started from, but by the other side. People can always come from "outside", by rocket. $\endgroup$ – wip May 19 '17 at 14:36

16 Answers 16


Tsingy de Bemaraha Strict Nature Reserve may give you an idea:

sharp rock pillars

Source for image.

I am happy for the chance to share this awesome image. This is in Madagascar and these sharp formations are limestone. Wikipedia says the name "Tsingy" means "the place you cannot walk barefoot". Nice short word for that.

I have never seen limestone weather this way and I don't know why it made knives here, but this is a weird and beautiful way for a place to be impassable.

You might get top on top of one and look around but that doesn't really help you find your way. They are too sharp and spaced too far to go along the top. Down below it is a labyrinth, and there are shorter rock knives down there too.

I envision this type thing enclosing the area. This makes a different impassable than mile high mountains or lava lakes or quicksand. A dangerous impassable, because you might try.

  • 11
    $\begingroup$ If I had to guess, you get limestone to whether that way when the strata has been turned 90 degrees from the horizontal. +1 for the awesome answer. $\endgroup$ – Joe Kissling May 16 '17 at 22:29
  • 1
    $\begingroup$ Amazing! I didn't know that surreal place existed. $\endgroup$ – BrettFromLA May 16 '17 at 22:46
  • 6
    $\begingroup$ @JanDvorak The forces that govern the Earth move entire contents, turning what amounts to a mountain on its side is literally nothing. $\endgroup$ – Joe Kissling May 17 '17 at 4:05
  • 4
    $\begingroup$ @JanDvorak I encourage you to seek out a geology textbook. Here is a satellite image of what I described. Technically folded and eroded, but the effect is the same. $\endgroup$ – Joe Kissling May 17 '17 at 4:15
  • 5
    $\begingroup$ @JanDvorak that's because that strata is not limestone, but it demonstrates the folding of huge areas of rock over time. However, this document references extensive cave systems eroding away to from the structures shown. It appears my initial guess was mistaken. $\endgroup$ – Joe Kissling May 17 '17 at 4:27

A large, deep valley with sheer walls, such as Yosemite Valley in California, USA, should only be accessible from the two ends of the valley. The Yosemite National Park website says it is a "deep excavation created by earlier glaciers".

enter image description here


A giant mesa (flat-topped mountain) might do the trick, if the sides are steep enough. The Grand Mesa, in western Colorado, USA, has a top that is 500 square miles. That's plenty big for your requirements.

If the sides are steep all the way around, some culture would have had to have created stairs or a ladder to access the top originally (assuming they don't have helicopters).

If the sides are steep in most places, but there are sloping parts of the mountainside as well, then people could use the sloping sides for access to the flat area on top.

I got this idea from Devils Tower in Wyoming, USA (and in Close Encounters of the Third Kind).

enter image description here


Thanks to TRiG for suggesting Tepui in the Amazonian jungle. Here's a picture:

enter image description here

  • 2
    $\begingroup$ Another alternative: the mesa is uninhabited, and you landed there with a parachute and you now have to survive on a 500 SqMi area that has never seen a human foot and doesn't have that much vegetation either. $\endgroup$ – John Dvorak May 17 '17 at 4:05
  • 11
    $\begingroup$ A Tepui is a large Mesa. There are some that have not ever been explored, and they often even have their own biosphere, having been physically separated from the surrounding land, so allowing evolution to take a different route. As an example. Auyantepui is the largest and is home to the Angel Falls. Tepuis should provide a good setting for diverse and different wildlife, instead of the USA mesas which tend to be more arid. $\endgroup$ – Baldrickk May 17 '17 at 8:29
  • 1
    $\begingroup$ A better example would be Island in the Sky: a large area of rangeland that only needed fifty feet of fence to keep the livestock in. $\endgroup$ – Mark May 18 '17 at 1:53
  • 1
    $\begingroup$ @Baldrickk. Here's a video of Tepui in the Amazonian jungle. $\endgroup$ – TRiG May 18 '17 at 16:37
  • 1
    $\begingroup$ Classic example: The Lost World by Arthur Conan Doyle. $\endgroup$ – Peter Taylor May 19 '17 at 16:51

A Crater

A meteor impact crater can easily fulfill what you are looking for. Here is a list of examples that you could draw from. Access points can be as many as you like, made by weathering and erosion. They can be where ever you want them to be on a planet.

Likewise, a volcanic caldera could also fit the bill. As a bonus, you can get residual volcanic activity as a plot device.

  • $\begingroup$ I was literally going to write the same thing. $\endgroup$ – JBiggs May 17 '17 at 17:52
  • $\begingroup$ @JBiggs I felt like a crater was self-evident $\endgroup$ – Joe Kissling May 17 '17 at 17:53
  • 1
    $\begingroup$ Santorini - island, caldera, AND sheer cliffs. :) $\endgroup$ – Mazel May 17 '17 at 21:52


There are only two access points: the upper one with France, not usable in winter because of the snow, and the lower one with Spain. A landslide on the lower road in winter could completely isolate the country (I think it actually happened in the 20th century, but couldn't find a reference)

It's a bit larger (180 sq mi) than your specifications, but it will provide you with an example of geography, culture and politics.


Islands are pretty insular. Each island of Hawaii, for example. (Or Gilligan's Island.)

  • 9
    $\begingroup$ "Islands are pretty insular." Especially since "insular" means "relating to or from an island" (from the Latin "insula", meaning "island"). $\endgroup$ – RonJohn May 17 '17 at 16:52
  • $\begingroup$ @RonJohn LOL! I honestly didn't know that. $\endgroup$ – BrettFromLA May 17 '17 at 17:27
  • $\begingroup$ Can people explain why «Islands are pretty insular.» is an acceptanle answer when «An atol might get the job done.» is not? $\endgroup$ – JDługosz May 20 '17 at 20:25
  • $\begingroup$ I think this could be elaborated into an answer, by explaining that isolation/insular means island, pointing out how this was historically true for several places, and is a common literary technique with some extra handwaving for modern times. $\endgroup$ – JDługosz May 20 '17 at 20:28


Virtually any canyon out there is accessible from only a few points (within the area you specified, obviously more in total). You could easily stop them by surrounding canyons. It doesn't have to be small either, the Grand Canyon is an example of that.

Mountain Ranges

Although they're usually bigger than your proposed area, this might not be the best solution, but it would certainly look nice and not suffocating like a canyon could. Japan has many mountains that you could look at, for inspiration. Let's put a picture in there (open in new tab to see it bigger): enter image description here

Dangerous Wildlife

You could put a few signs out there and tell the player that there's dangerous wildlife out there, so they should stay back. If they wander off too far, just sic a bear on them and take them down. This also presents the potential of hidden paths that could be explored without being eaten by the wildlife, if the player is brave enough. Although in real-life, the person could fight back, usually get beaten by the bear but fight back nonetheless. There could be roads protected by soldiers, therefore, only a few access points.

In general, huge obstacles are a good way to close the player inside a pre-defined space without making them feel restricted.


1) a river island. A dangerous, difficult to cross river splits into two and the 2 parts rejoin farther down stream, making an island in the river.

A river island — on the planet Earth — can be as small as a boulder sticking out of the water or as large as the largest river islands on Earth.


The river can be surrounded by flat land and almost impassible swamps or in the mountains surrounded by high canyon walls. There could be dangerous rapids and.or waterfalls above and/or below the river island. Or maybe the river is full of boat smashing, man eating monsters.

2) A river loop. A meandering river often has a total length many times the total distance from its source to its mouth because it has a lot of loops. Many Mississippi River loops are almost islands. And sometimes a storm will cut through the narrow neck and straighten the river and make an island out of a loop. Of course the Mississippi River has been used for communication by canoe and by steamboat for thousands of years, and presumably there would be many places to land along the loop, so you will have to make the river less navigable.

3) If it can be a city, how about Venice? A group of islands in a lagoon that cannot be easily reached by water if the islands are defended. Or Ravenna, a nearby city that was surrounded by marshes and almost inaccessible when it was the capital of the western Roman Empire.

4) Perhaps a (possibly abandoned) city? This is the size of Babylon as described by Herodotus:

  1. Assyria possesses a vast number of great cities, whereof the most renowned and strongest at this time was Babylon, whither, after the fall of Nineveh, the seat of government had been removed. The following is a description of the place:- The city stands on a broad plain, and is an exact square, a hundred and twenty furlongs in length each way, so that the entire circuit is four hundred and eighty furlongs. While such is its size, in magnificence there is no other city that approaches to it. It is surrounded, in the first place, by a broad and deep moat, full of water, behind which rises a wall fifty royal cubits in width, and two hundred in height. (The royal cubit is longer by three fingers' breadth than the common cubit.)


A furlong is 660 feet so 120 furlongs is 79,200 feet or 15 miles, giving Babylon a total of 225 square miles.

Of course Herodotus greatly exaggerated the size of Babylon.

Vijayanagara, capital of the Vijayanagara Empire until its terrible sack in 1565. The city center covered 40 square kilometers or about 15.441 square miles.

The whole city was full of gardens, and because of them, as an Italian visitor in 1420, Nicolo Conti writes, the circumference of the city was sixty miles. A later visitor was Paes, a Portuguese who came in 1522 after having visited the Italian cities of the Renaissance. The city of Vijayanagar, he says, is as "large as Rome and very beautiful to the sight"; it is full of charm and wonder with its innumerable lakes and waterways and fruit gardens. It is "the best-provided city in the world" and "everything abounds." The chambers of the palace were a mass of ivory, with roses and lotuses carved in ivory at the top—"it is so rich and beautiful that you would hardly find anywhere, another such.


Abdur Razzak, the Persian traveller who visited Vijayanagara in 1440 C.E. wrote of six fortifications before reaching the gates of the royal palace. The areas between the first and second and between the second and third fortification was large and contained agricultural fields, gardens and many residences. From the notes of Robert Sewell it becomes clear that between the third fortification up to the actual fortress, one came across countless people, shops, bazaars. From their accounts the area of the greater metropolitan area of Vijayanagara was about 540 km² which is about 25 times larger than the area comprising the main administrative, sacred and royal centers. The tourist zone itself is limited to the inner urban core.


If the greater metropolitan area of Vijayanagara was about 540 km² or 208.495 square miles, and it was surrounded by the outermost walls, and if it was mostly uninhabited after the massacre of 1565, someone could have bricked up most of the outer gates, leaving only a few gates open for entering or leaving the ruined city.

4) Possibly a (possibly abandoned) fortress. Ranikot Fort in Pakistan is believed to be the largest fortress in the world and encloses mostly empty desert. The gates would be the easiest ways in or out and they could be closed.


5) A rectangular plot surrounded by canals. From the description of Atlantis in Critias:

I have described the city and the environs of the ancient palace nearly in the words of Solon, and now I must endeavour to represent the nature and arrangement of the rest of the land. The whole country was said by him to be very lofty and precipitous on the side of the sea, but the country immediately about and surrounding the city was a level plain, itself surrounded by mountains which descended towards the sea; it was smooth and even, and of an oblong shape, extending in one direction three thousand stadia, but across the centre inland it was two thousand stadia. This part of the island looked towards the south, and was sheltered from the north. The surrounding mountains were celebrated for their number and size and beauty, far beyond any which still exist, having in them also many wealthy villages of country folk, and rivers, and lakes, and meadows supplying food enough for every animal, wild or tame, and much wood of various sorts, abundant for each and every kind of work.

I will now describe the plain, as it was fashioned by nature and by the labours of many generations of kings through long ages. It was for the most part rectangular and oblong, and where falling out of the straight line followed the circular ditch. The depth, and width, and length of this ditch were incredible, and gave the impression that a work of such extent, in addition to so many others, could never have been artificial. Nevertheless I must say what I was told. It was excavated to the depth of a hundred, feet, and its breadth was a stadium everywhere; it was carried round the whole of the plain, and was ten thousand stadia in length. It received the streams which came down from the mountains, and winding round the plain and meeting at the city, was there let off into the sea. Further inland, likewise, straight canals of a hundred feet in width were cut from it through the plain, and again let off into the ditch leading to the sea: these canals were at intervals of a hundred stadia, and by them they brought down the wood from the mountains to the city, and conveyed the fruits of the earth in ships, cutting transverse passages from one canal into another, and to the city. Twice in the year they gathered the fruits of the earth-in winter having the benefit of the rains of heaven, and in summer the water which the land supplied by introducing streams from the canals.


If your characters don't know how to swim, and don't know how to sail on the canals, or the boats are all docked on the opposite sides of the canals, they can only cross the canals where there are bridges. The squares made by the canals seem to have been 100 stadia or about 9.75 to 12.98 miles on each side. But you could make them different sizes if you wanted.

6) Perhaps a very specific setting. The Great Hedge of India was an internal customs barrier in the 19th century. By 1878 the great hedge had 411.75 miles of perfect hedge and 1109.5 miles of inferior hedge, or dead and dry hedge, or stone walls.

There were guard houses spaced along the hedge and gates on the roads with customs houses to collect the tax.

Imagine a meandering river that loops up to your fictional version of the hedge at two places and loops away from it in between. If the river is wide, or swift, or rough enough, there might be very few places to ford it, and few bridges. And there could be few gates in the hedge on the other side.

The segment of hedge could be replaced by a segment of Great-wall-of-China-like defenses if you want. But either way the inhabitants of the loop of land would be left on the outside looking in.

This might have been suggested by Buckland in LOTR, between the Brandywine River in the west and the High Hay keeping out the Old Forest in the east.

And there is the great wall on Skull island in King Kong protecting the village on a peninsula from the dinosaurs.

Added 05-19-2017.

7) Suppose that there is a river running north and south through the No Man's Land Valley between Westlandia and Eastlandia. Westlandia and Eastlandia are often at war, so each has fortified the cliffs on their side of the No Man's Land Valley with walls and a few gates.

Thus most of the fighting between Westlandia and Eastlandia takes place in the flatter ground north and south of the No Man's Land Valley. The No Man's River runs north and south through the No Man's Land Valley but it loops a lot, often hitting the east or west cliffs. Thus the No Man's Land Valley contains many larger or smaller sections of flat land that are surrounded on three sides by the hard to cross No Man's River and on the other side by the east or west cliffs with walls at their tops and guards at the few gates more likely to shoot you with arrows than let you in.


Just a valley to the sea seems reasonable. plenty of fiords answer the description. Sea access at one end, small approaches from other directions.

So similar to parts of Norway or in more tropical climes the Marquesas perhaps with valleys almost unapproachable except by sea.


Swamps filled with alligators and poisonous, hungry animals.

Extremely polluted and fast-flowing rivers.

Haunted, scary forest with wolves and werewolves, bats and vampires.


Radioactivity - maybe there was a war or a nuclear event.

Extreme weather - tornadoes, arctic cold, avalanches, mudslides.


In 2014 the ruler of Dubai announced plans for a climate-controlled domed city covering an area of 48 million square feet (4.5 square kilometers). Several such ideas have floated around for other cities as well [See Wikipedia]. I can imagine that there will be only a few well-determined exit locations from such a covered city.

Artist's visualization of the Dubai dome: enter image description here

Edit: I created an answer and only later realized the question states "average medieval person". Oops! I'll leave the answer in anyway in case someone is looking for a more contemporary/futuristic alternative.


Here is a great place to reference the Gandalara Cycle. It has seemingly fantastical geography which surrounds the world of Gandalara with rock walls thousands of feet high (in some places).

Do not follow the link if you do not want the ending of the story spoiled (or at least, do not read the "conclusion" section of the wiki article).

Map of Gandalara

In the last book of seven "The River Wall", it is revealed that this geography is actually scientifically feasible, but due to central plot piece spoiler, I will not mention why, exactly.


Have you considered a cultural barrier?

In the Stargate SG-1 episode Brief Candle the residents of Argos believed so strongly that their God would punish them if they dared venture outside the confines of their village, that none of them ever tried it. The belief was so deeply ingrained in their culture that leaving the area never occurred to anyone.

A simple myth or belief that bad things would happen if they leave, coupled with a negated requirement to leave (by ensuring they have everything they could need and want) would potentially be enough to keep a group of people in one place.

While the set on that particular episode of SG-1 was disappointing in that it wouldn't have looked out of place on Star Trek TOS, I did feel the plot was plausible enough to fit your requirement

  • $\begingroup$ I just re-read the question and realised that real world examples were asked for. I was about to delete the answer but instead I challenge you to prove SG-1 is not real ;) $\endgroup$ – Darren H May 18 '17 at 17:51
  • 2
    $\begingroup$ Stargate SG-1 is the beard for a real-life Stargate program just like Wormhold Extreme was on the show. Plus there is real-life Egyptologist named Michael Shanks. It all comes back around again, like a circle, like a Stargate. $\endgroup$ – Mazel May 19 '17 at 16:31
  • 1
    $\begingroup$ Uroboros confirmed! $\endgroup$ – Darren H May 19 '17 at 16:35
  • 2
    $\begingroup$ @Mazel indeed! See my answer worldbuilding.stackexchange.com/questions/46213/… $\endgroup$ – JDługosz May 20 '17 at 20:19

Since we're talking about cities, I'd like to bring an example to your attention: Mantova, in northern Italy.

As you can see on a map, Mantova is surrounded on three sides by lakes. The peculiarity is that those lakes are artificial: they were created in the 12th century by engineering the course of the Mincio river, exactly for strategical purposes: to make the city easier to defend from enemy attacks. Back then, the city was completely surrounded by water, as a fourth lake existed in the areas now called "Valletta Paiolo" and "Valletta Valsecchi"; this fourth lake was destroyed and dried because of urban expansion needs and health concerns (the stagnating waters were becoming increasingly unhealthy).

The project was majestic (for obvious political reasons), and was intended to make the city "look like an island" to outsiders approaching it.

While the Mantova lakes are indeed shallow, calm, and easily navigable, your fictional land could have a similar water body, maybe one that is artificially made stormy or otherwise hard to cross. Sort of like a river island, but an artificial one.


Bordered on all sides by impassible geography of some sort or another

Forgive me if I'm reading this wrong, but it can't be literally impassible on all sides, otherwise how would the inhabitants get in and out?

Anyway, it sounds like what you're describing is a castle.

That was the entire point of a castle; to have very few entry points possible for invaders. And where there was a place for entry points, people created their own impassibility: walls, moats, etc.

Here's a random sampling of castles I googled.

From gothic castles on Pinterest

Also, it may not seem like it to us today, with all of our modern tech like airplanes, antibiotics, and chainsaws, but things like a dense jungle on uneven terrain can be considered impassible. Also, features like swamps and bolder hillsides can be impassible, depending on what you're trying to pass through.


Mountains and swamps are popular barrier terrains but I'm thinking an ironbound coast on one edge and forests on the other cutting off a lens of arable farmland near the coast. The ancient North Forest Road is the only overland access route, the forest is cut by deep ravines and river gorges, the road takes the path of least resistance but no-one can believe some of those bridges were built without magic. The wildlife is undisturbed so much of the time that they have no fear of man seeing them simply as meat on two feet instead of the more usual four. The coast is almost all shear cliffs, rocky beaches, and strong currents, like the east coast of South Africa or the northern coasts of the Iberian Peninsula. The single natural deep water harbour acts as an easier access point for the country as a whole and the national capital is also it's main port. The overall topography is pretty flat but travel is still heavily restricted.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.