clever idea with a variety of possible implementations. Empires could be built over caves that interconnect regions, Caves could give short-cuts to exotic biomes - but whether such a cave is at all "safe" or simple to transit is something that might be an interesting design variable. Such caves might be prone to permanent collapse . . .
#suggestion: tunnels cave x
thin blaze
tropic moat
Well, this is segmental generation through gluing, in general, this is not something that developers are ready to take on now
tropic moat
lol I tried to add a picture with a link to supplement the post and it was deleted, I'm duplicating....
not man-made caves randomly located through which you can pass at x2 faster distance than above ground, they have obstacles and barriers that are updated over time, that is, if this is an active and widely used tunnel, it will be practically free of obstacles, thorns and other things, unlike the unknown
add: visualization of the "randomly" generated tunnel, its proportions and potential irregularities
and in the tunnel there should be an opportunity to move around the map
tropic moat
suggestion: tunnels cave x
thin blaze
tunnels like this could also serve as the long-dreamed "bridges" over rivers, but instead of going over, they could go under. The length of the cave could be adjusted to cost more for use than the direct swim-across option for casual travelers, but give a cart-pulling player a means to avoid unloading and reloading at crossings.
The tunnels could be implemented over time as alternative ways to cross between regions - like some kind of late-game subway system
limpid oasis
Just realized there was already this thread for Tunnels, so I'll add what I posted on the one Axucs made.
Do you mean like naturally generated caves which have various entrances on the outside, and when you go in, you can move between one entrance and the other and would need to run the same distance as if on the outside? That would sound interesting, maybe it would allow for more resources to be added in there, some mushrooms, ores, rocks, even animals. There could potentially be places where they become large enough for there to be underground settlements.
It would certainly be a way to add more depth to the game. 🐱