ToME WikiThe Orc Caves are located a few steps to the north of Bree via overland travel. There is a very small cluster of mountains around them, but the Caves should be readily visible when you approach them.
The Orc Caves are equivalent to dungeon levels 10 through 22.
Terrain: One-square-wide passageways, circular rooms lined with granite, and occasional "destroyed" type rooms (erratic borders and fillers). Occasional traps and terrain streamers.
Monsters: Well, what do you expect? 
Lots of orc types plus the occasional zephyr hound and human types (novice mindcrafters and the like), fairly low-level monsters. You may encounter some of the lower-level uniques here, such as Ufthak.
Special level: DeathWatch on Orc Caves 21.
Items: Mostly arms and armour, some tools, few rings and books.
Boss: Azog, King of the Uruk-Hai, guards level 22 of the Orc Caves. He drops the Wand of Thrain, a very nifty artifact digging wand that cannot be destroyed by recharging or the 4 elements (beware of certain wand-related traps, though).