For example, here's a few typical dungeon names:
The Crypts of ...
The Masoleum ...
... Sepulcher
The Tomb of ...
This suggests undead and vampires. I wouldn't expect to go into a natural cave with a name like this.
Ruins of ...
Another man build structure, perhaps.
Vermdon
Vermrock
Vermgod
Some dungeons have a unique cool name.
The Pit of ...
The Lair of ...
The Aviary of ...
The Hold of ...
The Groto of ...
The Den of ...
Nest of ...
... Cavern
... Cave
This seams to be a place where we will find some sort of stupid physical monster. Aviary refers to harpies and they usually live in abandoned castles.
The Citadel of ...
... guard
The Tower of ...
Castle ...
The Fortress ...
The Stronghold of ...
... Tower
Fortifications. A citadel may be a more developed fortification.
... Laboratory
... Asylum
... Shrine
Associated to scholars, rogue magicians and secret cults, perhaps.
... Rectory
... Web
... Hermitage
... Tunnel
... Cairn
... Hold
Don't have a clue about this.
The Quarry of ...
A mining exploration.
Coven in the ...
A witch coven?
Other places besides cemeteries, ruins and temples also have a lot of variety.
Some examples:
The Queens Barbarian
The Red Hedgehog
The Silver Wolf Hostel
These suggest road taverns or lodgings for travelers.
Arkhope
Eastbridge
Typical big cities with a fortified wall or homes using Daggerfall designation.
... Manor
... Court
... Hall
Manor and Hall is associated to feudal land rulers. All this fall in the Town category.
Old Lysausa's Shack
The Old Hawking Hovel
Don't have a clue about this. An hermit?
... Plantation
... Farm
This suggests farm lands.
There are no mining locations but there are mining related dungeons.
These sub-types might be used to determine what kind of npcs will be found inside a dungeon, if it they are compatible with certain quests or how the dungeon itself was generated. Do you noticed if this really happens in the game or is just a suggestion?
I guess that some of those huge dungeon sections could have been selected in association to a sub-type name. Some huge rooms suggest abandoned altars and sacrificial pits. There's a vast ruined castle section that sometimes is immersed in water. Some sections are prisons. Others have a wine cellar structure. There are underground rivers, cave sections and more i don't recall right now.