Castleguard Cave

Castleguard Cave is a limestone cave located at the north end of Banff National Park in the Rocky Mountains of Alberta, Canada. With 21,311 metres (69, 918 ft) of surveyed passages (as of 2024), it is Canada's second longest cave, and its tenth deepest at 388 metres (1, 273 ft). Castleguard Cave ascends gently from its entrance and terminates beneath the Columbia Icefield.