The Great Inland Lake was a vast deep lake (assumed to be bottomless) in the south known to be filled with dangerous pikes, and was once guarded by magpies until Mighty Megraw conquered them. It was centered by Marlfox Island, and was once the home of a water monster, the Deepcoiler. In Salamandastron the Island in the middle was the home of Urthwyte, Loambudd, and Ashnin.