Waimea may get lots of press for the giant winter waves in the bay, but the valley itself is a newsmaker and an ecological treasure in its own right. The Office of Hawaiian Affairs is working to conserve and restore the natural habitat. Follow the Kamananui Stream up the valley through the 1,800 acres of gardens. The botanical collections here include more than 5,000 species of tropical flora, including a superb gathering of Polynesian plants. It's the best place on the island to see native species, such as the endangered Hawaiian moorhen. You can also see the remains of the Hale O Lono heiau (temple) along with other ancient archaeological sites; evidence suggests that the area was an important spiritual center. Daily activities include hula lessons, native plant walks, and traditional Hawaiian games, depending on how many staff members are working on a given day. At the back of the valley, Waihi Falls plunges 45 feet into a swimming pond. Bring your board shorts—a swim is the perfect way to end your hike. Be sure to bring mosquito repellent, too; it can get buggy.