An area of more than 30 square kilometres in the Gampaha District was occupied by a water body and it’s referred as Negombo lagoon. Negombo is nearly 28 to 33 km north to the main city, Colombo and somewhat near to the Katunayake International Airport.
Negombo town is traditionally based on fishing industry and the economy mainly depends on tourism. Dandugam Oya, Old Dutch Canal and many other small water sources fed the lagoon and the outflow of the lagoon linked to Indian Ocean by a narrow canal. Negombo lagoon was considered as the most important venue during the colonial era by Portuguese, Dutch and British because of its importance for the transportation and administration. The lagoon extends for nearly 12km long and 2m depth. The lagoon is rich in both eco systems, terrestrial and aquatic. According to Directory of Asian Wetlands, Negombo lagoon is listed as one of the major wetlands of Sri Lanka.
As a good tourist spot of Negombo town, the lagoon welcomes tourists from all over. Old Dutch fort gate, Dutch cannel and Old colonial era churches are the other spots near to the lagoon.