The building at top is Spider Crypt, you can find almost identical building in Ujimasa Hojo's Nerubian set.
The small structure at lower right corner is the original model of ziggurat, you can find them within the editor as 3 hidden models that are unsuited for use other than being doodads, or simply download it's 3 tier re-creation from the hive.
That Necropolis with pool below is an early version of undead main building, of that version only the icon has remaint. You can find an similar model here on the hive, i remember ujimasa had made it.
On an different topic: Holy shit, Liches could summon Frost Wyrms at some point? whoa.