Massive Underground Cavern Formed During Ice Age Discovered By Amateur Explorers

Two amateur cavers discovered a massive Ice Age cavern entrance beneath the city of Montreal that is so sprawling it even contains an ancient underground lake.

Cavers Luc Le Blanc and his friend Daniel Caron, who have been exploring underground caves in the Montreal areas as a hobby for years, were stunned after they knocked through limestone discovered a massive chamber. The entrance to the cave, which is underneath Parc Pie XIII, near Highway 40, connects to Montreal’s Saint-Leonard Cavern.

The cathedral-like chamber formed in the Ice-Age more than 15,000 years ago and hadn’t seen human visitors until just a few months ago, CBC first reporter. The underground cave system contains stalactites, a massive lake and the end of the vast network of tunnels is still yet to be found.

The CBC crews who tagged alongside Le Blanc and Caron to explore and document the intricate underground passages were among the first people to see the newly found wonder. The duo noted that the chamber runs so far deep underneath Montreal it actually reaches the aquifer, or the water-bearing permeable rock from groundwater is extracted.

"This is a major discovery we made. This doesn't happen many times in a lifetime," said Luc Le Blanc, who found the passageway along with his friend Daniel Caron.

The two explorers waded through as much of the cave network as possible, before they used an inflatable canoe to navigate through the fifteen-foot deep water.

"It keeps going. We haven't reached the end yet," Le Blanc said. The two added that they had been searching for an unknown section of the Saint-Leonard cavern network for years and were amazed in October after digging past a thin wall of limestone that cut off the newfound branch.

"We started digging in a decomposed layer of limestone that was much softer...We managed to open a window through which we could see the void beyond," Le Blanc said. After opening a window-sized hole to peer through they then expanded it just large enough for an adult human to crawl through to the new chamber of caves.

Le Blanc and Caron described the hidden passages as beautiful and said that the discovery is important because of its mammoth size as well as the way it was formed over tens of thousands of years.

"The walls opened through the pressure of the glacier above … it's a mechanical process through a glacier. It's been called glacial tectonism."

Montreal and borough officials said they play to eventually open the caverns to the public following the appropriate surveys required for high-volume visitation to the newly discovered caves.