The City of Sogo & labyrinth below, on the 16th Planet of Tau Ceti (Fake

).
Certainly some odd canyons, created by changing a random procedural planet's Class in the planet editor.
They just showed up looking like that.
CPU: AMD FX-8350 8 core processor 4GHz / GPU: GeForce GT 730 @ 1920x1080, 60Hz with 1GB adapter RAM / RAM: Patriot Signature 4GB 1600MHz 240-Pin DDR3 (only 2GB work, don't buy it) / Motherboard: MSI 970 Gaming MS-7693