Everything non-mundane, basically. No fungi, bees, ants, temples, labs, military bases, bunkers and silos, mines. Strangely enough, rift map feature is still there, even if its not accessible. And there is certain secret building, but without anyone inside.
On the other hand, there is a ton of fema camps, farms, mansions and wood cabins, presumably, in place of labs and other countryside buildings.