Buried deep beneath the Grotto Mountain near Canmore is a system of deep caves known as the Rat’s Nest. Canmore Cave Tours runs guided trips into the maze of twisting passageways and claustrophobic caverns.
There are two core trips: the Explorer Tour (adult/child $125/105), a 4½-hour trip that involves around two hours underground; and the longer Adventure Tour (adult/child $155/145), a six-hour trip that features an 18m abseil and ends at the Grotto, a stalactite-filled chamber with a crystal-clear underground pool. Younger kids are permitted on the shorter Discovery Tour hike, which includes the cave's entrance.
Be prepared to get very wet and muddy, and brace yourself for chilly temperatures, as the caves stay at a constant 5°C year-round.