From PictureWritingPrompts - [Picture shows a cliffside town at the base of a very steep, zig-zagging road. Buildings of a small village cling to the side of slopes that are only mildly kinder than the almost sheer cliffs on either side of this town. There are a few jetties stretching into the dark water.]
A lesson must be taken from The Thaknakys Expedition. They had thought that they had found a graveworld on the other side of the newly-reopened wormhole. There was enough wreckage. Enough record of a global disaster in the form of a tectonic upheaval that rendered all the previously-habitable land inhabitable through rarified atmosphere. They should have looked closer at the ghost cities on top of tabletop mountains, edged in impossible cliffs. They should have checked the artefacts.
Humans had lived there.
If they had known that one, simple fact, they would not have set up airborne mining facilities to grind down the most likely-looking edifice until they accidentally encountered other tunnels made by other life forms. Who were, it must be noted, rather upset that someone else had just barged in and helped themselves without a by-your-leave. Fortunately, negotiations were brief and to the point. Reparations were made. Trading centres were carved out of the living mountains like Petra, only with more airlocks.