Difficult accessible Vratna river canyon is known from the antiquity by a stone gate and unusual whirlpools, miracle of nature. These stone arches or gates are over the river that incurred in the distant past by the caves destruction .The geographers call this stone wonders “Prerasti”.
The first gate is located about 200 meters from the medieval monastery, and the first detailed description of this area is by Austrian Felix Kanic, known balkanologist and great friend of Serbian people. Soon there came our geographer Vladimir Karic (1887) and then a founder of modern Serbian geography Cvijic Jovan (1885).
The third is the youngest and least accessible of the first two. At the same time is the most beautiful and the most attractive for researchers. Near by the third gate three so far unexplored caves are discovered. It is the "true charm of nature." Detailed investigations of the cave are just ahead, but speleologists says that the cave nearest the third gate is about 400 meters long, the second is a short but attractive, because it hides beautiful small lake. The third cave is very large and complicated, interwoven with numerous halls and tunnels.