Which Kerala lake is India's longest lake?

Vembanad is India’s longest lake, stretching about 96.5 kilometres through Kerala. It is also the state’s largest lake and the core of the extensive Vembanad–Kol wetland system.

The lake runs along or near the districts of Alappuzha, Kottayam, and Ernakulam, and has different local names. It is called Punnamada around Alappuzha and Kochi Lake near the port city. Rivers including the Pamba, Periyar, Meenachil, Manimala, and Achenkovil feed its waters.

Vembanad is closely tied to Kerala’s backwater culture. Houseboats travel its waterways, Kumarakom lies on its eastern shore, and the Nehru Trophy Boat Race takes place on the Punnamada stretch. The Kuttanad region beside the lake is famous for farming below sea level.

The Thanneermukkom salt-water barrier divides much of the lake into fresher and more brackish zones. Vembanad–Kol became a Ramsar wetland in 2002. A frequent mix-up is Chilika, India’s largest coastal lagoon, or Wular, often described as India’s largest freshwater lake; neither is India’s longest lake.