I'm working on a planet design which makes it feasible for several human-like societies to emerge and evolve separately, up to a point where they are capable to interact with one another directly with relative ease (in a pre-industrial stage). Imagine Europe, Asia, America and Oceania being remotely aware of one another until the 1500s where in the span of 200 years direct contact becomes the rule.

I'm looking for help infidning means to reconnect a world that has been disconnected by topology. I'm a scientist myself, so I'm not afraid of technical details.

My world

My current best candidate is a world with no oceans or large water masses (in liquid form). It has two icy poles and a desert belt. The rest of the planet is rich with biodiversity. The whole planet is carved by mountain ranges of huge altitude (+10km) that mostly transit in the direction of poles. Such topology creates isolated regions (those within mountain ranges that cant be crossed regularly) where different societies emerge and evolve.

The water cycle I assume for such world would be: clouds drop all water on high mountains (orographic lift), which leads to rivers and lakes here and there, which go into the direction of the poles, where water is frozen and clouds are generated and loaded again with moisture. The desert belt is the result of water not reaching the equator because of the high mountains. The icy poles I assume will be massive in both surface and height, since they must hold most of the water of the planet.


The problem is how a planet which is disconnected by topology can become connected in a relatively short time span. So far I have the discovery of new routes or mountain passes (hardly a breakthrough for advanced societies). The discovery of new flying technology (too much of a game changer). And the discovery of tunneling tech. The latter is my favorite, and I'm leaning towards mountains made of minerals particularly sensitive to temperature changes. This way, a primitive device applying ice and fire could act as a tunneling machine. Unfortunately, it is hardly enough to turn +10km mountains into easy routes.

Question: Is it feasible that pre-industrial societies perform large scale tunneling? Is there an alternative for reconnecting such a world?

P.D: I'm also happy to hear about alternative planets that could cause such a disconnected-connected social pattern. However, I'm not interested in sea centered worlds (I've read a couple of great posts on this forum in that regard). How to avoid boats on a mainly oceanic world? How to hinder the development of sea travel until the industrial age?

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    $\begingroup$ Welcome to worldbuilding. You are asking two different questions, while our model is 1 question per post, as you can read in our help center. That apart, I fail to understand how what you describe is any different from our Earth. $\endgroup$
    – L.Dutch
    Jul 19, 2021 at 14:33
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    $\begingroup$ ? Around 1500 Earth had quite a few almost completely separated world-economies -- Europe, India, China, Japan, Mexico, the Incas of Chile and Peru, the North-American Indians, sub-Saharan Africa, Russia etc. Then in two or three centuries all those merged into a globalized world. Which is to be expected: as long as transportation technology is not sufficiently developed, economic centers 1000 miles apart could as well be on different planets. Eventually, transportation technology reaches a point where 1000 miles is no longer another planet, but part of the practicable network. $\endgroup$
    – AlexP
    Jul 19, 2021 at 14:53
  • $\begingroup$ Hi Dario. Please note that on this site "feasible" (though used often) is a terrible word. It implies a comparison to real-life facts. We have only one data point to work with: Earth, and since most Qs ask about things that didn't happen on Earth, the only practical answer is "Nope, it isn't feasible." In most cases, what OPs mean is "believable," because suspension-of-disbelief is the primary goal here unless specifically asked otherwise (e.g., the hard-science tag). So, are you really looking for "feasible," or are you just looking for "believable?" $\endgroup$
    – JBH
    Jul 19, 2021 at 16:10
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    $\begingroup$ @JBH: But in the case of this specific question, the answer is that the situation is very obviously feasible, because it did happen on Earth -- and as far as we can imagine, it is bound to happen everywhere. Before the advent of practical long-distance mass transport, sheer distance was effectively an impenetrable wall between cultures. Even more so over land than over sea. In the 15th century there were more than a dozen independent civilizations on Earth; in the 18th, not so much. $\endgroup$
    – AlexP
    Jul 19, 2021 at 16:15
  • $\begingroup$ @AlexP You're point's well taken - but you're focusing on the premise of the question and I'm focusing on how to ask a good question. $\endgroup$
    – JBH
    Jul 19, 2021 at 17:45

1 Answer 1


Replace the mountain range with a deep valley.

Forget tunneling. It's too hard without modern tech.

Each civilisation occupies a tectonic plate. Some edges (where plates collide) are towering mountains that are impossible to cross, but some (where plates diverge) are gaping valleys.

These valleys are about, say 1km side to side. Say 400m sheer drops, with hot rocks, sulfur dioxide, and geysers at the bottom. The air is hot and toxic and very difficult to cross overland. The land is seismicly active, making primitive bridge building a waste of time.

Another advantage of valleys is they can see the other side without climbing - they know there are people on the other side so are motivated to try to connect. Mountains kinda block whats behind them.

Once they get to industrial age they can start building suspension or cable stay bridges without (or with minimal / flexible) supports, they can make contact.

After some early failures they'll be able to build earthquake-resistant bridges that span the entire valley and get in contact.

Once the roads are linked their societies interlink.

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    $\begingroup$ I like the solution (and will keep it) but I wonder if building bridges over such toxic, massive valleys is actually easier than doing tunnels. If you cannot cross it at ground level (because of poisonous gasses or even lava), can you really pull cables from one side to the other? $\endgroup$
    – Dario
    Jul 20, 2021 at 12:16
  • $\begingroup$ There are ways to build bridges without having to lug a big heavy cable accross the ground. "Canon, grapling hook, thin rope pulling over thicker rope" is an obvious one, but I was thinking more "tower on one side, extend tiny flimsy deck to other using temporary cable stay, cross it, build tower on other. Replace cables with wtronger ones. Strengthen deck.". But we could also go "workers build base using poor ppe" - by the time you have industrial revolution some protective equipment should be available allowing shifts in the hazard valley. Same as ceoson disease / golden gate bridge. $\endgroup$
    – Ash
    Jul 21, 2021 at 1:03

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