The Shallow Lands was the gnomish name for an enormous underground cavern about as geographically large as the entire Kingdom of Narnia. It lay in the subterranean nation of Underland, directly beneath the lands of Narnia, Ettinsmoor and the Wild Lands of the North and directly above the sub sub terrain nation of Bism. Most of the floor of Shallow Lands was covered by the water of an underground lake called the Sunless Sea. At the northern end, the waters were shallow enough to wade in, and the land there was called the Pale Beaches. At the south end of the cavern, the lake ended and a rocky mountain rose up into the cave, whereupon the Lady of the Green Kirtle had her Dark Castle built.