Gargantua

The largest natural cavern in Canada, 290 metres long, under the Crowsnest

Under the Andy Good Plateau, on the line between Alberta and British Columbia, is a limestone cave with 6,001 metres of known passage as of 2002, running 286 metres deep, and inside it is the LARGEST NATURAL CAVERN IN CANADA: a single chamber 290 metres long, 30 wide and 25 high. There are five ways in, including one called the teapot entrance and an exit through a waterfall, and the hazards listed for it are ice and squeezes, which is caving shorthand for a place that will hurt you if you are not equipped for it. This is not a visit. It is an expedition undertaken by people with rope skills, cold-weather gear and somebody at the surface who knows where they went. It is on the map because a chamber that size under a Canadian mountain is worth knowing exists, and because the Crowsnest is full of people who have driven past this plateau their whole lives without being told.