Eglise Saint Leonard, Montreal
St Leonard's Church in Saint Leonard's neighborhood of St Leonard Wikimedia Commons/Chicoutimi

You would not have any inkling surveying the Montreal landscape, that a 250-metre stretch of cavernous caves dating back to the Ice Age lie underneath the surface.

But that is exactly what two amateur cave explorers have discovered underneath the Park Pie XII in the Saint Leonard's neighbourhood, last October.

The St Leonard Cavern was initially unearthed in 1812. Daniel Caron and Luc le Blanc, two amateur 'cavers', suspected the cavern was not isolated. For two years, they drilled through one of the cavern's limestone walls and finally got through in late October. It confirmed their suspicions: there was a complete network of caves buried underneath the park and residential area surrounding it. Le Blanc branded it the "void beyond".

The walls of the cave run six metres high, and the main 'room' is adjoined by several pathways leading to similar caves. The 'corridors' walls are perfectly parallel to each other and studded with stalagmites and stalactites.

Caron explained that the caves, which date back 15,000 years, were formed under the pressure of massive receding glaciers, resulting in cracks in the rocks, which explains why the marks on the walls could fit each other like puzzle pieces. .

"Normally you have to go to the moon to find that kind of thing," said Caron during a recent press tour.

Apart from the main chamber discovered in 1812, Caron and le Blanc are sure they were the first explorers to visit the caves.

"They've dug sewers and made basements, but no one had ever seen them," Le Blanc said

According to Caron, the only way to discover caves is through human exploration.

"Underground excavation is the only thing on the planet where there is no scientific, technical or technological means of knowing if there are caverns, and whether they are large or small."

Thus far, the dynamic duo and their team have discovered about 250 metres of caves, but suspect there might be even more. One of the chambers was filled with water and they are considering hiring divers to literally get to the bottom of the matter.

More rock climbing, crawling and rock breaking will be required to understand just how far the caves go. Caron and le Blanc are members of Quebec's speleological society.

Speleology Society of Quebec's director, Francois Gelinas, said the caves will eventually be opened to the public for visits. But the most intrepid will have to be patient - and wear rubber boots. Reaching the cave is only possible by crawling through muddy tunnels and using scale ladders across narrow passages.