Broken Ruins, the smallest of the ruins, are comprised of several rooms on a couple levels. Their common presence in the bamboo of the Mountain Forest and sun-motif of some of their component blocks hints of both Chinese and Japanese architecture stylings.
There are two variants of the Broken Ruin. First is the above-ground variant which is always found in much better conditions and only has Coyotes guarding it. Second is the subterranean variant which always appears much more broken down and has both Titanomyrma Drones and Titanomyrma Soldiers guarding it.
Broken Ruins have the lowest-tier creatures guarding it, making it the easiest dungeon to raid for new or low-level survivors.