A Network Of Caves Dating Back To The Ice Age Has Been Discovered Under The City Of Montreal

‘Normally, you have to go to the moon to find this kind of thing.’ This is an exceptional discovery that two speleologists recently made underneath Montreal in Canada. While exploring a small tourist cave located in the borough of Saint-Léonard, they uncovered a vast network of previously unknown caverns.

The Saint-Léonard cave was discovered in 1812 and has since become a famous tourist site in the city of Montreal. For a long time, specialists suspected that the 130 foot cavern could extend further than previously thought and be connected to other caves. However, the hypothesis could not be verified, at least not until now.

In 2014, two speleologists, Daniel Caron and Luc Le Blanc, began exploring the underground cavity some 30 feet below Montreal in order to find clues to the existence of these extensions. A year later, in 2015, they were able to identify a narrow crack in one of the walls.

At least 800 feet of unknown caverns

‘At the end, there was a small hole, very small,’ Daniel Caron explained to a journalist from Quebec Science who was able to follow the specialists. ‘Luc and I had long since become convinced that there was a void behind it. With a rangefinder and then an endoscope, we were able to confirm that there was a passage on the other side.’

Two years later, on October 12th, the duo finally managed to open the passage and were surprised to discover that the crack hid a much larger cavity than they had expected: about 20 feet high, 10 feet wide and more than 650 feet long. Better still, as they continued to explore, specialists discovered that it was linked to other passages.

To date, between 800 and 1600 feet of underground caverns have been identified, with perfectly vertical walls, a very horizontal ceiling as well as many stalactites and stalagmites. ‘It's still fantastic to discover a new space like this in Montreal,’ Daniel Caron said.

Others to discover

These limestone caverns were formed during the last ice age, between 10,000 and 15,000 years ago. It is believed to be the result of the rapid retreat of glaciers which, due to the pressure they exerted on the rock, created cracks in the ground. Cracks that would then have spread creating the Saint-Léonard caves.

According to the two speleologists, the new caverns have probably never been visited since their formation and others remain to be discovered. Nevertheless, the exploration of these structures is far from easy since they reach the Montreal water table, resulting in a water level that is too high in some areas.

These conditions have led Daniel Caron and Luc Le Blanc to interrupt their research for the time being. They are now waiting for winter, when the water table shrinks, to return to explore the rest of the caves, which could extend at least another 160 feet. ‘It goes on,’ concluded Luc Le Blanc to CBC News, ‘we haven't reached the end yet.’