The Muthurajawela Marshland developed over 7,000 years ago and covers an extent of 7,580 acres. In 1996, the northern section of the marsh came under the protection of the Flora and Fauna Protection Act. It is also the largest wetlands in Sri Lanka, located south of the Negombo Lagoon. This habitat is a valued ecosystem, preventing soil erosion and harbouring many types of wildlife.
The wetlands hold 192 varieties of plants and rare endemic wildlife like the Red Slender Loris. Visitors to the marshland can go on guided excursions supervised by the staff at the Muthurajawela Marsh Centre.