Sasthamkotta Lake in Kollam district is the largest freshwater lake of Kerala. Underground springs are the source of water for this lake. The lake holds about 22,390 million litres of water and serves as a source of drinking water for half a million people of the district including Kollam town.
The lake water doesn’t contain any salt, mineral or metal. It is home to about 27 species of freshwater fish including pearl spot and cat fish and two varieties of prawns. It is due to this that this wetland of international importance had been designated as an ecologically protected Ramsar Site in November 2002.
The lake is surrounded by hills on three sides and on the southern side, there is a bund separating the lake from the nearby rice fields. A country boat cruise through the lake is a nice experience. There is a Sastha temple on the banks of the lake, signifying its name. The temple is home to a tribe of peaceful monkeys while the nearby market is populated by a mischievous tribe.