Sunken Tomb

Spawns
Rock Golem

Sand Crab

Whorl

Clay Man

Bosses
Colossus

Wandering Vagrant

Imp Overlord

Scavenger

Acrid (Unlocks class. Can be found in the upper right corner of the map. If you see water, you are not at the top right corner of the map).

Artifact
The artifact contained in this area is Enigma. One variant of the map contains an area in the lower right hand corner. You will need to "drown" at least twice in order to get to the artifact(and then a third time to get out again). See the screenshot(right).