Vrelo Cave - One of the Deepest Underwater Caves in the World

Vrelo's entrance is hidden along the Matka Canyon, about 1.5 km from the Matka Dam. It forms a canyon lake covering about 5,000 ha. There is also a ground section above the cave's entrance, called Suva, famous for its stalactites and stalagmites.

Vrelo Cave has many stalactites including a large one in the middle of the cave, known as the Pine Cone, due to its shape. There are two lakes at the end of the cave, one larger than the other. The smaller lake is 8 m (26.2 feet) at its longest length and 15 m (49.2 feet) in depth at its deepest point. The larger lake is 35 m (114.8 feet) long and 18 m (59 feet) deep. Though the exact depth of the cave is unknown, some speculate that it could be the deepest underwater cave in the world.

Located on the right bank of the Treska River, the cave was listed as one of the top 77 natural sites in the world in the New7Wonders of Nature project.

It was explored by diver Mark Vandermeulen who was also part of this year's diving team. Vrelo ranks 14th on the list of the deepest caves explored by humans.

The cave is located in the Matka Canyon, near Skopje, which boasts 1,000 plant species, 20% of which are endemic, as well as various butterfly species not found anywhere else in Europe. The canyon is also home to vultures, and occasionally bald eagles, which are protected by law to preserve them from extinction.

The Italian cave diver Luigi Casati, who is part of an international team of explorers, tried to prove that the cave is at least 500 m (1,650 feet) deep. During the first dive, Casati reached a depth of 140 m (462 feet). He discovered several tunnels that branch off in different directions at a depth of 125 m (412 feet). After several attempts, Casati reached 205 m (676 feet), setting a new world record for cold water re-breather cave diving.

The total penetration so far has been around 280 m (924 feet), according to the diving team. Casati is using Aquatek Voyager re-breathers and a bail-out open circuit decompression line with different gas mixes. At this point, the dives did prove that the Vrelo Cave system is the deepest spring in the Balkans. The team, which includes Alan Kovacevic, Alen Milosevic, Alessandro Fantini, JJ Bolanz, Lorenzo Del Veneziano, Luigi Casati, and Tihomir Kovacevic, will continue to explore the cave and hope to penetrate much further.