Muthurajawilla Wet Land Sanctuary is a Wetland area of 2,000 hectares between Colombo and `, set aside as a unique tropical wetland, with its flora and fauna of marshes, waters and mangrove forests. Visitors can set sail on guided boat rides through the different ecological settings of the marsh sanctuary and the lagoon, or walk in nature trails and watch birds. Some 40% of the vertebrates of Sri Lanka are recorded here.

Plant life is also rich-the marsh vegetation includes mangroves, ferns and many kinds of grass and sedges. Birds are numerous. Commonly sighted species include Cormorants, Storks, Bee-eaters, Kingfishers, Grey Herons, Purple Coots, Little Green Herons, Yellow Bitterns, Black Bitterns, Moorhens and White-breasted Waterhens.