Ulthven Kreath

Ulthven Kreath is an underwater temple, first encountered in the Pieces of Hate quest, where the player fights Rabid Jack. After the quest, four murals can be found here which can be deciphered to obtain 50,000 experience in Agility, Construction, Firemaking and Thieving.

During the fight with Rabid Jack a large black hand will appear in the large hole in the middle of the temple. This hole is a portal to another world or dimension but it is closed with a giant stopper at the end of the quest after Rabid Jack falls into the hole.