I would like to create a world that is rendered nearly impossible to navigate by natural circumstances. In my particular world, a thick jungle covers the whole planet from pole to pole; this gives the planet an eerie monotonous vibe. I'm trying to account for as many variables as I can. I'm not sure how optimistic I should be about making the planet 100% impossible to navigate, maybe it's going to be a bit of a stretch to account for everything. Nonetheless, I want to make sure there are no glaring loopholes in this regard.

The following are brief notes on my progress thinking through barriers to navigation on my planet as they stand:


  • Visibility: The immense understory level of the jungle has no sunlight whatsoever. This also means navigation by the stars or other celestial bodies will be not be feasible.
  • Landmarks: Due to the monotonous landscape of the planet, it will be likely that there are few if not no distinguishing geological features. This will make it more likely for potential navigators to walk in circles as they are biased by their lead/dominant leg over time.


  • Tools: Primitive civilizations will not have GPS or compasses for that matter, so advanced navigation tools are clearly out of scope. However, I am not certain whether a primitive navigation tool could be brought to bear in my jungle world.
  • Forest Felling: Moreover, tools used to chop the trees down would certainly simplify things. I would like to make my world robust to this somehow.

  • Climbing: Even deprived of tools, the primitive civilization could climb trees and thereby extend their vision.

The above are simply the strengths and weaknesses as I perceive them. You may have your own set of strengths and weaknesses to making navigation as impossible as possible (pun not intended, but oh well). I'm allowing the latitude to approach this question with my particular logic weaknesses in mind, or your those imposed by the answer-er him/herself.

Question: How close to impossible can navigation be on the aforementioned Jungle Planet? Pardon the superlative nature of the question's phrasing, I don't mean for it to get too subjective. If the collocation "how close to impossible" doesn't sit well with you, you may replace it with "how difficult".

Further Clarification

  • Technology Level: Stone Age
  • Flora/Fauna: Existent, hostility is up to you
  • Planet Size: Roughly 1.5x the size of Earth
  • Seasonality: I'm not stipulating anything, but ideally it would be perpetually summer
  • $\begingroup$ So you're trying to find ways to make this planet as difficult to navigate as humanly possible for this stone age civilization? Are we trying to keep it somewhat realistic or are we going all the way down fantasy-lane here? $\endgroup$
    – DMQ
    Dec 31, 2017 at 11:00
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    $\begingroup$ I honestly don't think this requirement makes much sense. If your planet is un-navigable, how do animals get around? Species need to be able to find their den, locate a mate, remember where the salt lick was, etc. Then, if animals can find their way around, shouldn't people be able to as well? $\endgroup$
    – kingledion
    Dec 31, 2017 at 11:51
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    $\begingroup$ To build on @kingledion's comment, stone-age communities need to hunt, get water, and expand. No jungle is so dense that you can't follow rivers, climb trees to view the surrounding, and find paths between plants. A jungle can be unnavigable for a vehicle, but I can't suspend my disbelief enough to accept one that a skinny native can't navigate. After all, our stone-age jungle ancestors did. And that was before deforestation. $\endgroup$
    – JBH
    Dec 31, 2017 at 15:50
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    $\begingroup$ This question confuses modern navigation with navigation by palaeolithic people. They will be quite competent at learning landmarks, specific trees, trails, the terrain, & so on. Indigenous Australians used "maps" in the form of marks on sticks to follow specific tracks. Please don't underestimate Stone Age people, if there's a way they'll find it. $\endgroup$
    – a4android
    Jan 1, 2018 at 4:41
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    $\begingroup$ The single method of low-tech jungle navigation that I know of is marking the bark on the back of the trees, both to enable following a straight line and to get home again. But I imagine there are more. $\endgroup$
    – Bookeater
    Jan 1, 2018 at 9:13

2 Answers 2


Well-nigh impossible

I'm going to have to add another restriction: the jungle can't reasonably extend very much in the upper latitudes. With little axial tilt, you're still going to get a very low insolation at the poles.

You can start with a water world with no real landmasses at all, but very shallow seas. The planet would also need to be geologically inactive, so very small molten core with next to no radioactive isotopes (or you would get tectonic activity and orogenesis), and no magnetosphere worth speaking of.

Life arose in the oceans, progressed to algae, and the planet found itself surrounded by an equatorial Sargasso Sea with large algal mats. Then, competition for the sunlight drove the algae ever upwards, forming a thicker and thicker floating cellulose layer with no life beneath (no sunlight).

There are no rivers, no mountains, no landmarks of note. The wind is more or less constant above the canopy. Competition to rise higher and higher in search of sunlight drove the flora to develop lignine analogues and wood, while roots suck water from the floating layer, drying and compacting it.

In the end you get:

  • floating mat, bog-like, tens or perhaps hundreds of meters thick; in many places it reaches the bottom of the sea.
  • living humus layer, with fungi and assorted saprophytes, living in perpetual twilight. This is the "inhabitable" zone.
  • trunks, very hard, thin, flexible and rising some tens of meters; not suitable for climbing.
  • verdant canopy, extending as far as the eye can see.
  • every place is very much like everywhere else.

There is no stone or metal available, and it's very difficult to discover (and maintain) fire. Technology has little chance of evolving beyond bones, leather, ropes and sticks. Felling trees is a losing proposition.

(In some places, it could perhaps be possible to excavate a dry enough area to be able to reach the sea floor without water infiltrating, or the walls caving in).

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    $\begingroup$ "and no magnetosphere worth speaking of" which would have impact on atmosphere as solar winds would take the oxygen out of it making it more similar to Mars. $\endgroup$ Dec 31, 2017 at 15:42
  • $\begingroup$ Yes, that was why I made that observation. The world would have lost a lot of hydrogen and light gases even before life appeared. However, Marsification is slow, and there would be a habitable window several hundred million years wide. Plus, mutations would be more frequent due to lack of shielding. $\endgroup$
    – LSerni
    Dec 31, 2017 at 16:24

If they can live there, and move about their village, then they can probably move to the next village over. And the next one after that. And so on. You will not be able to prevent people from traveling, and stories moving from campfire to campfire. That being said:

Boats are an easy way to travel. Make the rivers lethal.

  • Something like a cross between a shark and a crocodile lives in most rivers, nasty enough to discourage small fishing boats. And if there are no small boats, who will learn how to build big ones?
  • Something like a piranha, so not even wading through a ford is safe.
  • Remember to keep a food source for those predators. Humans can go fishing, but only from shore.

No beasts of burden.

  • All land animals are unsuitable for riding, and especially for pulling carts. When all commerce is on the back of people, there will be less of it.
  • If you want riding beasts, e.g. to have knights in shining armor, make them so hungry that they are too expensive for commerce. Only important people will ride.

hostility to strangers.

Getting villagers to be afraid of their neighbours is tricky. Stone age people on Earth traded thousands of miles.

  • Villages rely on some plant that will grow slowly and only in a few spots (the right soil/humidity/whatever) as a small but vital part of their diet. Having other people find and harvest these "vitamin berries" would be a disaster. Trespassers are hunted down.
  • If you can accept a low total population number, make the stands of these "vitamin berries" far apart. Villages exist around their sacred tree, they can't exist anywhere else.

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