International speleological expedition will research August 2-15 cave Vrelo in Matka canyon to determine its depth. The goal is to reach depths larger than 183 meters, thus declaring Vrelo the deepest underwater cave in Europe.

Vrelo, which was nominated for the new Seven World Wonders, has been researched for several times. Its horizontal length is 450 meters and 98 meters in vertical, where from a new gap opens which bottom has not been reached.

According to speleologists' assessments, Vrelo's depth is 330m, thus being the deepest underwater cave in the world, surpassing the Bushman Hole in South Africa, which holds the Guinness Record with 282 meters.

Vrelo divers will also attempt to topple the European diving record of 182 meters.

The expedition includes two Macedonian divers, as well as five from Belgium and six from Italy.