Kushtarajagala is a rock-cut figure beside the Matara road, usually identified as a Bodhisattva image. It is easy to miss if you are moving fast through Weligama, but the carving is one of the town's few old sights and makes a good break from the beach.
The image stands in a shallow niche with little ceremony around it. Go early or late when the traffic is lighter, and combine it with the inland lanes behind town rather than treating it as a major excursion.