https://www.msn.com/en-gb/travel/news/massive-chamber-like-cavern-formed-during-ice-age-discovered-by-amateur-explorers/ar-BBGhO1J?li=AAnZ9Ug
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.