The damp cave is a part of the caves under Oasis.
The damp cave is a cave that connects the Grove with the sunken chambers. It is accessed via an Easy-locked underwater door from a pond in the grove. Inside there is a small contaminated lake (5 RAD/sec) with a few mirelurks and a few mirelurk kings (the number depends on the level of the Lone Wanderer). There are several junk items floating on the water of the small lake and on the bottom of the small lake. Several skeletons can be found under water. On the small beach, several items can be found next to a skeleton. On the east end of the room, a skeleton can be found next to an ammunition box and a sniper rifle.
A bottle of Nuka-Cola Quantum can be found on the small beach next to a skeleton.
The damp cave appears only in Fallout 3.