The Shabla Tuzla is located about 6 km east of the town of Shabla on an area of 250 hectares. It is a salt water lake, i.e. a lagoon, formed mainly by the seepage of salty sea water under the sand dunes. The origin and ecological characteristics of the Tuzla show that this small lake is a unique coastal ecosystem with an extremely rich plant and animal life. There are 13 species of rare and endangered plants listed in the Red Data Book of Bulgaria. 41 species of nesting birds have been recorded. Southeast of Durankulak, separated from the sea by a wide sand spit, is the Durankulak Lake, formerly known as Eagle Lake. The "swamp," as the locals call it, is not very deep and it covers area of 5x2 km.