Latyan Dam (Persian: سد لتیان sad-de latyān) is a buttress dam on the Jajrood River, located less than 25 km from Tehran in the south of city of Lavasan.
It is one of the main sources of water for Tehran metropolitan region. It was constructed between 1963 and 1967.In a close distance of this dam’s lake there are two beautiful forest parks called Letian and Telo.
Travellers can play different water sports on this dam such as boating, water skiing and fishing.
Reference
http://en.wikipedia.org