Muthurajawela is the largest saline coastal peat bog in Sri Lanka. The Marsh together with the Negombo Lagoon form an integrated coastal wetland eco-system with marsh lagoon complex itself estimated to have originated around the year 5000 BC. The northern section of the marsh covering an area of 1,777ha was declared a sanctuary in July 1996 under the fauna & flora protection ordinance. The marsh is a major local and tourist attraction, primarily used for sightseeing and boating tours, and the area also supports local agriculture and forestry. Visitors to the region are guided through the sanctuary areas by the staff of the Muthurajawela Marsh Centre to avoid serious harm to the marsh ecosystem.