The Vembanad Lake is the largest brackish lagoon in Kerala. It covers an area of two hundred square kilometers and is surrounded by the districts of Alappuzha, Kottayam and Ernakulam. Situated at sea level, the lake is separated from the Arabian Sea by a small island. The width of the lake varies from five hundred metres to four kilometers with a depth of one metre to twelve metres.

The rivers flowing in the lake are Achenkovil, Manimala, Meenachil Muvattupuzha, Pamba and Periyar. There are three islands located in the lake Pathiramanal, Perumbalam and Pallippuram. The majority part of the lake is in Kottayam District. The Periyar River evacuates into the lagoon in the north and the Muvattupuzha River in the central part.

The port of Kochi is located at point where the lake merges into the Arabian Sea. The Vembanad Lake has been marked as a wetland of International importance under the Ramsar Convention. The northern extension of the Vembanad Lake at Vyppen Island in Cochin is called Veeranpuzha. The banks of the Vembanad are covered with evergreen to semi-evergreen trees and also densely covered with coconut trees. The shores of the lake attract a large number of water birds. Kumarakom Bird Sanctuary is located in the vicinity.

The Vembanad Lake is an ideal picnic spot and provides exciting opportunities for boating and fishing.