La Verna Cave

There is a giant cave in France.

It has a very large room inside. A river falls down the wall into the room.

Small bugs live in the dark. These bugs have no eyes. They do not have colors. They need the damp air to live.

People can visit the cave now. You can walk through it too!

La Verna is a huge cave in France.

It has the largest underground room in the world. This room is called the Salle de la Verna. A river falls down the wall into the room.

The river flows into rocks at the bottom.

The cave formed a long time ago. It began about 200,000 years ago. A river found a path through limestone rocks. Limestone is a type of rock that can dissolve in water. As the water moved, the cave grew through a way called solution and collapse. This means the rock dissolved and then fell in.

Special animals live in the dark cave. They are small bugs called invertebrates. These bugs are blind and have no color. They need very damp air to stay alive. Two kinds are the Aphaenops loubensi and Aphaenops ochsi.

People can visit the cave now. A company built a dam to make power. They use the river to make electricity. The cave opened to the public in 2010.

La Verna is a famous show cave in France. It is located in the commune of Sainte-Engrâce.

This cave system is part of a much larger area. This area includes the Gouffre de la Pierre Saint-Martin and the Gouffre des Partages. There are fourteen known entrances to this system. Inside, you can find the Salle de la Verna. This is the largest underground chamber in the world. It is a truly massive space for people to explore.

This huge chamber formed a long time ago. The process began about 200,000 years ago. It happened through a way called solution and collapse. A river flows from limestone plateaus into the cave. This river finds a path through limestone rocks. Limestone is a type of rock that can dissolve in water. As the water dissolves the rock, the chamber grows.

Eventually, parts of the rock collapsed to create the room. The river now cascades down the east wall. It then sinks into boulders at the bottom.

Many people have explored these deep, dark places. In 1952, explorers were working in the area. During these trips, a man named Marcel Loubens died after a fall. A group of Lyon scouts called La Verna Troop helped with the rescue.

This group helped give the Salle de la Verna its name. In 1953, a team of explorers discovered the chamber. They were the first to find this giant room. They even wrote their names inside the cave.

Strange animals live in this dark, wet world. They are small invertebrates, which are tiny animals without backbones. These creatures are blind and have no color. They must live in air that is very damp.

Two common kinds are Aphaenops loubensi and Aphaenops ochsi. A biologist named Michel Cabidoche studied them in the 1960s. Now, Professor Arnaud Faille leads a team to study them. They want to see how these animals change over time.

Today, people can visit the cave to see it. A company named SHEM worked to make electricity there. They built a dam and a small reservoir. They also put in more than 500 meters of pressure pipe. This helps turn the river's energy into power.

In 2010, the cave finally opened to the public. Now, everyone can visit this amazing underground world. Even people with reduced mobility can go inside. It is a place of great wonder for all.

La Verna is a massive show cave located in the commune of Sainte-Engrâce. It sits within the Pyrénées-Atlantiques department of France.

This cave is part of the Pierre-Saint-Martin karst area. This area includes the Gouffre de la Pierre Saint-Martin and the Gouffre des Partages. There are fourteen known entrances to this entire system. The system contains 13 underground rivers and many passages. Explorers have mapped a total of 150 kilometers of passages, chambers, and shafts.

The most famous part of this system is the Salle de la Verna. This is the largest underground chamber in the world. The chamber is incredibly vast. It has a diameter of 120 meters. The height reaches 150 meters. It covers a surface area of 10,000 square meters. The total volume is 1,000,000 cubic meters. Inside, a river cascades down the east wall. The water falls halfway down the wall. It then sinks into boulders near the base of the chamber.

Geologists explain that this chamber formed through solution and collapse. This process began roughly 200,000 years ago. The river starts at infiltration zones on limestone plateaus. The water flows through soluble Cretaceous limestones. It eventually reaches a base level where it flows over insoluble schists. These schists are part of the Paleozoic basement rocks. The Salle de la Verna formed where the river moved from schist onto Devonian limestone. As the river found a new route through the limestone, it left the old passage dry. This old passage is called the Gallerie Aranzadi. The walls of the chamber show the unconformity between the Paleozoic and Mesozoic rocks.

Exploration of these deep caves has a long and serious history. In 1950 and 1951, explorers found the Lépineux shaft. At that time, it was the deepest shaft ever descended. On August 13, 1952, an explorer named Marcel Loubens died. He fell during an exploration and suffered a fractured skull and spine. He fell into a coma and died 36 hours later.

A group of Lyon scouts called the La Verna Troop helped with the rescue attempt. The chamber was named after this troop. One year later, on August 13, 1953, a team discovered the Salle de la Verna. The team included Georges Lépineux, Jimmy Théodor, Daniel Eppely, Michel Letrône, and Georges Ballandraux. They met inside the chamber and inscribed their names on the walls.

A unique community of animals lives in this dark, underground world. These animals are small invertebrates. They are blind and lack pigmentation, meaning they have no color. They must live in an atmosphere saturated with humidity to survive. Two common species are Aphaenops loubensi and Aphaenops ochsi.

These insects have a very specific life cycle. After fecundation, the female lays a single egg. A small larva hatches from the egg. Unlike surface insects, this larva metamorphoses directly into an adult. It does this without feeding first. The biologist Michel Cabidoche studied them in the 1960s. Today, Professor Arnaud Faille leads a team from the French national museum of natural history to study them.

Humans have also used the cave to produce energy. Between 1956 and 1960, the French National Electricity Company (EDF) tried to build a tunnel. They wanted to capture the underground river for electricity. They spent four years digging, but the project was abandoned. In 2000, a private company called SHEM restarted the project. Work began in January 2006. They built a dam across the river where it enters the chamber. This created a small reservoir of 15,000 cubic meters. They installed more than 500 meters of pressure pipe. This pipe goes through the tunnel and down to a power plant in the valley.

Today, La Verna is a place where science and tourism meet. The cave opened to the public on July 1, 2010. This happened because of cooperation between SHEM, cavers, and local authorities. A small company created by cavers now organizes guided visits. The cave is accessible to everyone. This includes people with reduced mobility. Visitors can even see a standard four-person hot-air balloon fly inside the chamber.

The cave remains a major site for both studying geology and observing unique life forms.