The Snow Chasm is a region located underneath the Snowy Wasteland to the west of the large tree, about halfway to the bridge. It descends all the way down to the bottom of the map, stopping just short of the lava sea running underneath The Laboratory. At the very bottom, you'll find an orb room.
The Snow Chasm consists of several layers of two differing tilesets, one with blocky shapes and wide open spaces, and one with swirly patterns. Just like in the Desert Chasm you will need spells for digging to get anywhere as there are no continuous corridors, only dead ends.
Just like for the Desert Chasm, a case can be made for the layout in this region to just be a placeholder. A patch may come someday that does something to revamp the area.
This area contains many dangerous, powerful enemies, some of which can not be damaged unless a Paha Silmä is nearby.
and possibly some others...