Sunless Sea

The Sunless Sea is a great subterranean lake that lies under the land of Narnia. The capital of Underland, a great seaport, is located on its pale beaches. All outlets to the Overworld lie on the other side of the Sunless Sea, with the exeption of the secret tunnel dug by the Earthmen in preparation to invade Narnia. The Sunless Sea, along with the whole Underland are unknown to the surface world until the capture of Rilian.