Glacial Crevice is a location in The Elder Scrolls V: Dawnguard. It is a sublocation of the Forgotten Vale, that is inhabited by Falmer villagers. It is a large cave system deep inside the canyon.
There are multiple hidden chests or entrances underwater, so waterbreathing is recommended. There is a hidden underwater cave that connects the first section of the lake to another, farther section. There is a small basin between them that contains several dead Falmer floating underwater and a chest on top of some ice on the surface.