Broken Bridge by NotDazlek, Broken-Bridge.nodes (11342) - it was probably hit by a meteorite or something. in case you couldn't tell, there are lots of lines in this

Bast YT Endscreen by NovalRoihan [YT], Bast-YT-Endscreen.nodes (1607) - <3 ya

Ancient Room Background by Epitaph, Ancient-Room-Background.nodes (1992) - A long forgotton and most likely underground passage.