On the hillside west of Unawatuna, this impressive pagoda was built by Japanese Buddhist monks of the Mahayana sect in 2005, as part of their scheme to build peace temples in conflict zones (the Sri Lankan war was raging at the time). It's a (steep) 20-minute hike from the west end of Unawatuna beach, if travelling by road you have to use a narrow 1.6km access road from the highway. The views of Galle Bay and the ocean are spellbinding at sunset.
Dress modestly, though the caretaker may lend you a sarong. There is another pagoda built by the same monks in Ampara, on the east coast.