Strange Down Here

The Old Ones warn the young of the Temple, the place where Time dies. Ancient people came from the surface to create the Temple, where they changed and transfigured themselves that they might live among the seafolk. When they were done with the Temple, they made one last sacrifice, of the Oldest Old One, to guard their treasures; and they gave him guards of his own, and they killed Time, that they may never lose their treasures, not even to one of their own.

The Temple is hidden, in a barren place, far from the land of Life and Time. Things that wander in never wander out. The Old Ones say it often, until the young have it memorized: if you go in, you can never come out.