A deep, narrow canyon gorge has been formed on the Arda River, near “ Studen Kladenets” dam . It is called Sheitan (Devil) by the locals and is about a kilometer long. In the narrowest places the rocky shores are almost vertical with a height of 5 to 10 m .The width of the river is 1 to 6 metres and the depth is up to 20 meters. Before the construction of the dam, people used to hear a creepy roar coming from the water. Today the gorge has significantly less water, but still impresses with its size. The landscape is unique.
Legend has it that once the border between Bulgaria and Turkey passed here. A Bulgarian soldier made a bet that he could manage to steal a sheep from the Turkish territory and jump across the river with it. TheTurkish officer, who witnessed the incident was amazed by the strength of the soldier and shouted "Sheitan" i.e. no man but a devil. The gorge bears this name ever since .