Do any of you stop and investigate something every time you fly somewhere in JC3? Happens all the time to me.
Maps are all created by hand. A game developer basically uses a mouse pointer to move areas of the map up and down and depending on how steep it is, the development program automatically adds grey rocks to the edge of the hill/cliff/hole and black "darkness" into the bottom if the hole is deep enough. (I saw this demonstrated at a development vlog for some other game.) The northern side of Insula Striate even has giant straight lines going across the landscape where the ground looks compressed, or something.
Anyway, every time I fly somewhere I "notice" something potentially very suspicious, only to fly closer and find that it was a random big rock, or weird random crater.
Example of a random crater: N 40 44.665 E 5 35.950.