Erosion

Despite being trapped underground, things actually start looking up for Steve once again. The structure he finds is an extraterrestrial ship, crashlanded there hundreds of thousands of years ago. The life forms onboard that managed to survive the crash knew they could survive off the recources surrounding them. They set up a makeshift headquarters which had several beds with dividers around them. Basing mining operations from it, they eventually managed to become more and more advanced. The makeshift civilization mysteriously disapeared over many years. No one could ever figure out why the empire fell, however Steve may be about to find out.

Additional Notes

The answer to this riddle is hidden in the map somewhere, will you find it?