Neglected for decades, Waimea Valley is now a nonprofit botanical garden and preservation area that offers workshops on Hawaiian history and culture, as well as performances and educational demonstrations. “It’s a beautiful valley and, I would say, a very sacred place,” Mr. Johnson said, referring to Waimea’s deep roots in Hawaiian history and traditions, including the remains of sacred sites, houses and shrines — some believed to have been constructed around 1470 A.D. “There’s a nice waterfall at the back of the valley and there’s a long trail that’s accessible for everyone,” he said, referring to the nearly mile-long paved path that winds across the valley to Wailele Falls. Along the trail, are magnificent examples of “native plants and tropical plants from around the world,” as well as interpretive signs that provide insight into the flora, fauna and history of the valley.