Decades ago, pairs of professional marathon swimmers used to compete as 2-person teams in the 24 Heures La Tuque. Its course was a mile-plus swim around the shoreline of a circular lake in Quebec, Canada. Around and around the lake they went day and night for 24 non-stop hours, one person swimming at a time.

While La Tuque is near the southern edges of Quebec, there is another interesting circular lake – a crater lake – located on the opposite side of Quebec in the north.

The 400m-deep Pingualuit Crater (Inuktitut, “where the land rises”) is 3.4 km (2.1 miles) in diameter that rises 160m above the surrounding tundra and contains some of the purest water in the world. The lake has no inlets or apparent outlets, so the water accumulates from rain and snow and is only lost through evaporation. It might be a totally cool place to swim with a carbon-neutral escort.

Photo by © Robert Fréchette.

Copyright © 2013 by Open Water Swimming