Begin with a relaxed exploration of Negombo town, its churches and fishing areas, then spend some time around the lagoon or Dutch-era canal.
Stop for a seafood lunch before heading towards the beach. Negombo is better enjoyed slowly than by trying to fit in a long list of attractions.
Finish your day with a walk along the coast at sunset and an easy dinner near the beach. If Negombo is your first stop in Sri Lanka, use the evening to recover from the journey before travelling further into the island the following day.