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The Saint-Leonard Cavern

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Did you know that there’s a cave right in the heart of Saint-Leonard?

It’s rare to find a speleological site in the middle of any big city; those that exist in Quebec are becoming less and less accessible as time goes on. However, the cavern that lies in Saint-Leonard’s Parc Pie XII, not far from Autoroute 40, allows visitors to wonder at geological mysteries dating all the way back to the ice age, without even leaving the city.

The Saint-Leonard cavern formed as a result of a fissure in rock caused by passing glaciers about 10,000 years ago. Despite the cave’s young age, the Speleological Society of Quebec’s website claims that calcified fossils have been found on the site that are believed to be over 450 million years old! Imprints of seashells and corals are most commonly spotted in the space.

The Saint-Leonard cavern is 35 meters long with a drop of eight meters. The site’s entrance leads visitors to a rectangular room measuring 13 meters long, two meters high and three meters wide. Further in, they’ll find a five-meter deep well that’s accessible by ladder for discovery. The average temperature underground is about 5°C, and the relative humidity registers at nearly 100%.

The first mention of the site appeared in a newspaper called the Spectator back in 1815 – curious Montrealers have been flocking to the spot to discover it for themselves ever since. In 1980, over a century later, the cave’s entrance and nearby grove would be declared an official cave site.  In 1988, the Communauté Urbaine de Montreal deems the Saint-Leonard Cavern a historical site, taking measures to preserve and protect it.

Unsurprisingly, the cave, located in the middle of a now bustling, developed neighbourhood, piques the imagination of many a Montrealer and has spawned a number of stories and legends over the years. For example, it’s been said that the First Nations occupied the space once upon a time, and that the Patriots used the site to store arms during the Rebellion of 1837. As of today, little evidence has been found to support either of these tales. Why not go on the hunt for yourself? Guided tours are offered every day this summer by the Speleological Society of Quebec and by the borough of Saint-Leonard.