Feel the cool spray on your face. That’s the Exsurgence de Port-Miou. This underwater spring is a marvel. It’s nestled in the heart of the Port-Miou calanque near Cassis.
The Exsurgence de Port-Miou isn’t just any spring. It’s a geological wonder. Its origin remains a mystery. A slight surface current and a thin layer of scum mark its presence. The spring mixes its icy fresh water with the warmer seawater. This creates a unique underwater environment.
For centuries people have observed the Exsurgence de Port-Miou. Its swirling waters have been a local landmark. In 1953 divers first explored the underwater river. They found it extended over 2200 meters into the earth. It’s a vast network of submerged galleries. The main gallery is about 20 meters wide. It descends to at least 233 meters below sea level. It’s one of Europe’s longest underwater rivers.
Many attempts have been made to harness the spring’s water. The hope was to provide fresh water for the region. In 1976 a subterranean dam was built. It aimed to stop saltwater intrusion. Sadly the water remained slightly salty. The project was abandoned. The dam now serves as a base for scientific exploration.
The Exsurgence de Port-Miou is a treasure. It’s a source of scientific research. It continues to fascinate scientists and divers. New species have been found here. The mystery of the spring’s origin remains. It’s a powerful reminder of nature’s secrets hidden beneath the surface. The Exsurgence de Port-Miou’s story is one of exploration and wonder. A testament to the natural beauty and the enduring mystery of the Calanques.