Kekaha Kai State Park
It's slow going, down a 1½-mi, narrow, bumpy, gravel road off Highway 19 to this beach park, but it's worth it. Kehaha Kai State Park encompases three beaches (from north to south, Mahai'ula, Makalawena, and Kua Bay, which has its own entrance). Mahai'ula and Makalawena are beautiful, wide expanses of white-sand beach with dunes; there's a lot of space so you won't feel crowded. There are tidal pools for snorkeling and swimming, and you can hike along a historic 4½-mi trail to Kua Bay. If you're game, work your way to the top of Puu Kuili, a 342-foot-high cinder cone whose summit offers a fantastic view of the coastline. However, be prepared for the heat and bring lots of drinking water. The park is busy on the weekends. Watch out for rough surf and strong currents. Amenities: toilets. Best for: swimming; walking; sunsets. www.hawaiistateparks.org.