The Vile Reef is a colorful reef portion of the Great Sea near the southwestern tip of the Eastern Kingdoms, mostly noted by travelers on the west coast of Stranglethorn Vale near Grom'Gol Base Camp. It is populated by murlocs who inhabit sunken troll ruins among the reef. It is possible that the Vile Reef holds the ruins of the ancient city of I'lalai. The Altar of the Deep can be found here.
It could be possible that the ruins were sunken during the Great Sundering.