The Kara Dag ("Black Mount") is a volcanic rock formation which rises to a height of 577 meters between the Crimean coastal town of Koktebel and the Otuzka River valley. It was the site of a marine biological station in the early 20th century. Some 2874 ha of coastline and 809 ha of coastal waters have been protected as the Kara Dag Nature Reserve since 1979. The littoral is rich in picturesque cliffs such as the Devil's Gate.