Thanks to a 1960 eruption by the volcano goddess Pele, which altered underground springs, visitors can take a warm dip at Ahalanui County Park on the remote Puna Coast east of Hilo. Until then the pool had been cool.
The free park is just one of the discoveries on Hawaii's most underrated coast, which also includes the Kehena-Pohoiki Scenic Drive. A sun deck surround's Ahalanui's seaside pool, and coco palms shade grassy picnics areas. Check out page 160 of Hawaii the Big Island Trailbazer.