Castleguard Cave

Castleguard Cave, a limestone cave at the north end of Banff National Park in Alberta, is Canada’s second longest cave and its tenth deepest. Extending beneath the Columbia Icefield, it is renowned for its remote setting, difficult access, long underground traverses, and unusual glacial ice plugs at its far ends. The cave formed mainly in gently dipping limestone and includes ancient abandoned drainage passages that were dry at least a million years ago. It is also important for rare cave formations, biological study, and continuing exploration. Known to Indigenous people long before its first recorded visit in 1921, it has been formally explored since 1967 and is now carefully managed through controlled access.

Alberta · Canada