Two Friends Discovered a Huge Ice Age Secret Lurking Deep Beneath the Streets of Montreal

Daniel Caron spent his childhood in the ‘60s exploring Saint-Leonard Cavern, a cave running beneath the Montreal neighborhood bearing the same name. From the very start, he had developed a taste for adventure — and more specifically, a love for the world beneath.

He would often get in trouble with local authorities for his night-time trips along the depths with his friends, which ultimately birthed his fascination with caves. Five decades later, he showcased the power of his hobby on a much larger scale, revealing something mind-blowing lurking underneath the town.

For three years, Cavern and fellow caver and friend, Luc Le Blanc, had a hunch that something lies beyond Saint-Leonard Cavern’s walls. When the time came where they could finally break through to the other side, all their suspicions were confirmed.

Concealed between the layers of decayed rock and limestone was something they suspected had managed to stay hidden from view for years and years, and this discovery was about to change their entire life.

What was so special about Caron and Le Blanc’s discovery in the darkness of Montreal’s underworld? It was something that was left behind and had been there since the last Ice Age that ended roughly 10,000 years ago — a time when the woolly mammoths inhabited the great wilderness of Canada.

The startling relic was now open to a group of selected visitors after a whole millennium. It was estimated that the relic was formed more than 15,000 years ago and had managed to remain untouched by modern civilization, all thanks to how well concealed it was.

The province of Quebec is home to almost 1.78 million people, so it’s hard to imagine that something of this magnitude could remain hidden for so long. With that said, Montreal hasn’t always been a metropolitan hub filled with life, hustle, and bustle.

Originally, the region was home to Hochelaga, a tiny secured settlement established by First Nations people. It can be assumed that people were never this curious about unearthing the mysteries of the cave because, to an average person, the cavern was like any other — dark and old.

Coming back to the history of Montreal, the French colonists arrived there in the 16th century, transforming Hochelaga into a Christian mission followed by an outpost specialized to trade in fur.

However, Montreal saw real prosperity when the land came under the rule of the British who conquered it — alternatively known as New France — in 1763. The settlement was located along the banks of Saint Lawrence River; another reason it was quick to blossom into a transport and manufacturing hub.

Canada was unified back in 1867 and, by then, Montreal became the largest city in the whole country. It was able to maintain this position for more than a century before being overtaken by Toronto.

Today, Montreal is the second-most populous metropolitan zone in Canada, housing more people than Ottawa, which is the capital. It’s noteworthy that Ottawa lies about 120 miles to the west of Montreal. An impressive 59% of the population can speak both English and French.

Montreal sits on the southern tip of Quebec and has long been acknowledged as a place that celebrates cultural and linguistic diversity. Every year, millions of tourists flock to the city to check out local attractions like the annual Jazz Festival and the Botanical Garden.

If you’re a fan of large-scale races, Montreal also hosts the Canadian Grand Prix organized by Formula One. So much cheer surrounding it, and yet they remained unaware of the secrets just below their feet.

Montreal grew in name and fame, and so did the closeby Saint-Leonard Settlement. Eventually, it was consumed by the city in 2002, turning into a borough of the greater metropolitan zones. A huge number of Italian-Canadians call Montreal home, especially those whose families immigrated there post World War II.

It’s safe to assume that since there was plenty going on above ground, people were less than concerned about what was happening or what had happened underneath them. After all, they never could have perceived what was lying down below.

In 1812, a large cavern spanning over 100 square feet was found under Pie XII Park of Saint Leonard, but early wannabe cavers wouldn’t have great luck exploring it. Before the average man could even develop an interest in the cavern, a conflict broke out across the region.

Within 25 years, people of what is now known as Southern Quebec rebelled against their government. With that, chaos spread and people’s minds were occupied by other thoughts. It was one amazing opportunity wasted.

Although still unexplored for the most part, the cave was being taken advantage of to the fullest. Not only did it serve as a decent hiding spot for the rebels, but it could also be used as an arsenal.

The military was able to suppress the opposition in 1838, drawing a conclusion to the conflict now known as the Patriot War. Deep down in Saint-Leonard Cavern, the voices dimmed and things fell silent again.

Decades went by and the cave became nothing more than a footnote in Montreal’s otherwise rich history, overshadowed by the metropolitan’s fancier attractions, but the feeling might have been very different for the children who found something interesting about the sinister and dark aura radiated by the underground chamber.

It definitely held its own appeal, no matter how “creepy” it seemed. This was what drew Caron closer to the cave and finally to the discovery. He grew up in a neighborhood near Saint-Michael.

Caron can attribute his passion for spelunking, as well as underground exploration, to the fact that he was living in close proximity to Saint-Leonard Cavern. During his teen years, he along with his friends made numerous visits to the area in an attempt to find something unique, despite the fact that the cavern was off-limits to the public.

Even though they would run afoul with the local authorities, they succeeded in entering the chamber at least once. This goes to show how strong their determination was.

It is possible that curiosity wasn’t the only thing poking young Caron to go out of his way to explore the underground channel under Pie XII Park. In fact, many minds of the Montreal caving community believed that the 1812 discovered cavern was hiding secrets of its own, and what was found was just the surface they were scratching at.

Whatever it was, it had been lurking in the dark for ages. Little did they know, they were inching closer and closer to a discovery that would leave them in absolute shock.

It would be several more decades before Caron would learn the actual deal with the cave. In the meantime, a lot of changes took place to the overall look of Saint-Leonard Cavern.

Although closed off by the government after being deemed too risky in 1968, the members of SQS — or the Quebec Speleological Society — decided on opening the cave to experts in 1978, allowing them to study the cave’s unique geological properties. Soon enough, the cave was declared a historical landmark.

City officials slowly started to realize that locking off Saint-Leonard from the general audience wasn’t doing them any good. Given its massive popularity, they could easily use it as a tourist attraction.

So, in the years after that, rather than driving the inquisitive visitors away, officials created an access point and issued permissions for guided tours. The main portion of the cavern was accessible by people for a long time, but the secrets still laid deep within the walls — stronger than ever.

Measures were taken to develop the overall visual aesthetics of the cave. A metal gate and door were constructed at the cavern’s entrance. As they secured the opening, they hoped to keep trespassers like Caron and his buddies at bay.

However, when it comes to people like Caron, who were born dreamers and unafraid, it’s extremely difficult to stop them from following their thoughts. In the meantime, a set of steps was built, making the trip into the cavern’s heart much less challenging. A rough, shabby road isn’t everyone’s cup of tea, after all.

The design immediately worked its magic. The new ease of access made Saint-Leonard Cavern the center of attention, driving in tourists from all across the world. It is believed that more than 70,000 visitors have taken a tour of the popular destination since it was first opened to the public in 1982.

However, all the while, the rumors kept wafting through the air — reminding people that there might be more to the cavern than meets the eye.

Caron had probably realized that he couldn’t do much about his fascination with the cave unless he joined the association entrusted to take care of it — the SQS. Le Blanc also joined the SQS, and the two became friends. This made exploring the caves of Quebec more of an official investigation.

Even with their growing knowledge of the area’s underground networks, their own doubts about the mysterious Saint-Leonard Cavern refused to dissipate. So, one fine day, they decided to get to the bottom of things.

That year, the two spelunkers set out with everything they needed to reach the furthest end of the cave. Le Blanc chose equipment that used radio waves to signal whether or not a passage or void could lie beyond the existing cave.

Bear in mind that this event occurred during the mid-2010s, a time when technology was developed enough to help with further and better exploration of caves. However, Caron chose to ditch the high-tech gear, picking out something decidedly more on the old-fashioned side.

British newspaper The Guardian stated that Caron relied on the age-old practice of dowsing to locate anomalies situated in the depths of the cavern. This bizarre technique is believed to have originated sometime in 16th century Germany.

The concept is using rods to detect resources like metal or water within the landscape. Now, don’t think of Caron as a fool just yet. It was his dowsing machine that did the majority of work — which we will be getting into a little later.

In recent times, dowsing is widely thought to be a part of pseudoscience. Despite this, it has continued to be used in a professional environment — such as in the UK, where workers use the method to locate main water pipes.

With that, maybe it wasn’t so unnatural that Caron chose to bring this technique with him when he set out to explore and unearth the secrets of Saint-Leonard Cavern. Would he find anything important? Was he going off on a wild goose chase? Only time would tell.

Unfortunately, Caron and Le Blanc’s attempts didn’t reveal much in the first few times, but it’s understandable given how inconspicuous the cave’s surroundings had been. However, it was in 2015 when they noticed a little gap amidst the rock walls — just large enough for a small camera to enter.

They referred to fellow caver François Gelinas and, with his help, they were able to take a closer look. What they found changed their lives and the history of Saint-Leonard Cavern forever.

One look at the camera footage, and Caron and Le Blanc knew their hunch had been right all along. The cavern was effectively hiding something, and they could try to find it out, but there was just one major problem — the thick wall of limestone separating them from the other side.

Their only hopes of reaching it was using industrial drilling equipment to break through the wall. You would think that this would prompt the officials to move faster, but it was actually quite the opposite.

It took almost two years for the spelunkers to take the investigation further. In October of 2017, the team was able to drill into the cavern wall and take down a section of the rock. Le Blanc talked with Canadian television network CBC the same year where he explained how they started excavating a decomposed layer of limestone that was significantly softer, making things easier.

After some persistent efforts, they succeeded in making a window with enough space for a grown human to squeeze through — they found their window of opportunity.

Caron and Le Blanc managed to squeeze their upper bodies through the window where they glanced at their newest discovery. It was a huge deal! A gigantic chamber existed on the opposite side of the rock wall.

In 2017, Caron spoke to local newspaper Montreal Gazette, and he gave them a vivid description of what they discovered. When they saw it, they could hardly contain their excitement — they had done it! They were still far from the finish line, though.

The next day, the two friends journeyed back to Saint-Leonard Cavern with their minds set on making it through the newly found chamber. They started enlarging the opening only to realize the drop on the other side was too big, restricting entry completely.

They somehow managed a ladder and slipped it down the crack before lowering themselves down into the darkness. They weren’t sure of what awaited them, but they were pumped to find out. After all, it was the discovery of a lifetime.

They climbed down the ladder and took their torches out, shining the light into the pitch darkness. The cavers realized they were in a space about 10 feet wide and 20 feet tall. Remember when we said this was the discovery of a lifetime?

Caron confirmed his achievement in his interview with the Montreal Gazette, commenting that this isn’t something that happens very often for a spelunker.

Interesting fact — the cave Caron and Le Blanc discovered is actually way bigger than Saint-Leonard Cavern, the one guarding it. It branches off in multiple directions from the primary chamber.

They noticed that some places were blocked by water, indicating that the furthest corner could only be reached if they followed the water. The underground passage was filled with a body of war, and stalactites posed so many unique challenges to the brave cavers. They simply had to press on ahead to find out the truth.

The passageway started to slope down once they crossed the wall. They kept going until they came across the aquifer. At this point in the route, the water ran even deeper and the ceilings hung very low.

They had no choice but to retreat. However, they came back very soon with an inflatable boat. It was time to tread the waterways in style, and they were determined to find the very end.

Caron described the aquifer — water source — in an interview with National Geographic. The aquifer from under the streets of Montreal is what supplies the cave with water.

For your information, an aquifer is simply a fancy term for an underground rock that stores water like a sponge would. The pools in the cave are a maximum of 16 feet deep in some places. In his CBC interview, Le Blanc mentioned how the cave seemed endless.

Although the keen explorers are yet to map every inch of their discovered underground passage, there’s no denying that what they have managed to uncover so far is incredibly impressive.

Le Blanc talked about the interior of the cavern with National Geographic in which he described them as “perfectly smooth” with the ceiling being “perfectly horizontal.” However, due to the excessive stalagmites and stalactites, the even surfaces have decayed in some spots.

Mineral formations, ones that grow up from the ground and down from the ceiling, have been spotted in caves all across the globe. According to the SQS, the growth rate of these formations is about 0.4 inches every 1,000 years.

From the pictures taken by Caron and Le Blanc’s discovery team, it’s evident that the cavern has been around for a while now. This led scientists to dig up old receipts to understand how long it had been since the cavern first formed.

So, how do you think the secret chamber was formed beneath Montreal? Experts say that it’s uncommon to find caverns this far north. Le Blanc further discussed the events that kickstarted a cavern formation.

According to his comments with National Geographic, caves are generally created when water eats away at the rocks for many years, but Quebec is a colder part of the world where temperatures may dip to -31° Fahrenheit, giving the water a lower level of acidity. Thus, caves form slowly, making them rarer at those latitudes.

In his interview with CBC, Le Blanc later added that the discovery was significant, not only due to the size of the chamber but also because of the way the cavern was formed. He further explained that the walls opened due to overwhelming pressure from the glacier above.

This glacier-induced mechanical process is termed glacial tectonism. In this, a glacier pushes into a sequence of sediments that were organized from before. Le Blanc was excited to explore the rest of the cave, and that’s exactly what they planned on doing.

Experts believe this cave was formed some 15,000 years ago. Back then, Canada along with the rest of the world was going through the last Ice Age. An enormous glacier formed in the place where Montreal currently stands, exerting tremendous pressure, which caused the rocks underneath to crack.

Now, in the 21st century, the single fissure developed into two awe-inspiring caverns. The cathedral-like chamber is believed to hide valuable information about the Ice Age, just waiting to be discovered.

Le Blanc stated that signs of the process are visible to this day. In talks with National Geographic, he said that the evidence is so striking that if there’s a knob on one side, there’s a hole on the opposite side of the wall to accommodate the shape perfectly.

Well, according to him, the rocks are so organized that they can be slotted to make one giant jigsaw — and this is just more evidence to prove the age of these caverns.

Ironically, on account of Caron’s former “failed conquests,” news of a new cavern’s discovery was postponed until officials could properly secure the location. Presumably, the region’s authorities weren’t over the moon about a bunch of amateur explorers snaking their way into a brand new network that was hiding in plain sight.

With that said, a few lucky visitors were able to catch a glimpse of the cave, as well as the reporters who were taken on a tour in December of 2017.

They stopped exploring the passageway after successfully mapping almost 500 feet. There’s a rigorous procedure associated with the discovery where the cavers must conduct precise surveying to make sure none of the houses on top are getting affected by what’s happening at the bottom.

Waiting for winter, the cavers drew up plans that predicted the cavern would run another 164 feet. Countless streets and houses were built over these grounds and yet everyone remained unaware of the spectacular sight that existed below their feet.

The cavern holds special significance to the people of Montreal. Saint-Leonard city councilor Dominic Perri expressed his excitement for the future plans regarding the cave with Global News.

He talked about how it’s a unique thing in the world. Normally, when we think of caves, we think about one situated in the depths of faraway mountains. This one is right in the middle of the city, giving the people a beautiful scientific discovery to enjoy. At the same time, he wants to make sure no one destroys it.

Finally, it can be hoped that similar to Saint-Leonard Cavern, this new chamber will be open for public tours soon, but first thing’s first — experts wish to research on and document the interesting geology.

David Perri, in an interview with Montreal Gazette, talked about how scientists expressed the unusual nature of the cave. The city hopes to maintain it not only because it’s an important part of their heritage, but also due to the scientific significance it bears in terms of how it was made and shaped.