Ice Caves

The top of the wall is completely covered in ice, the falls above are visible from the clear blue color. The water used to run down this corridor, back when it was older, as a large river. As the waters slowed and the place got colder, it began to freeze. Air bubbles trapped above caused the ceiling to look rounded and smooth, and when the water in the pathway unfroze and cleaned out and the top stayed, it became a perfect entrance to the Cerrac pack's lands.