This wetland which is 372 hectares in extent is protected as a sanctuary and is under the Department of Wildlife Conservation. Even though industrial wastes are released to the waterways that flow through the marsh, this, once a very rich wetland, still hosts many interesting species of birds. How to get there:- Colombo- Nugegoda- Pepiliyana- drive towards Bellanwila Temple, as you pass the temple, turn to left and after 30 metres turn to right again. This road goes through the marshes. You can also go past the temple for about 200 metres and turn right towards the "Pump House"of the Water Resources Board from where a footpath of about 1/2 km extends into the marsh along the river. BIRDS: Lesser Whistling Teal, Asian Openbill, Purple Heron, Blyth's Reed Warbler, Pallas Grass Hopper Warbler, Ashy- & WhiteBrowedPrinia, White Ibis, Black-Headed Oriole, Purple Coot, Water Cock, Common, Pied, White-Breasted & Stork-Billed Kingfishers, Black Winged Stilt, Spot Billed Pelican, White-Breasted Water Hen, Ruddy Crake etc.