3. Explore Hawai’i Volcanoes National Park, Hawaii Island

From desolate swaths of black lava to dazzling, cloud-kissed rain forests, the glory of Hawai’i Volcanoes National Park lies in its impossibly diverse landscapes. With 333,086 acres and seven ecosystems to cover, the challenge is in the planning—but two roads can steer you to the most essential sights. The 11-mile Crater Rim Drive circles the summit caldera of Kilauea, one of the world’s most active volcanoes. Worthwhile stops include Steam Vents, where you can watch steam rise from the Earth’s interior, and 500-year-old Thurston Lava Tube, a natural—and walkable—tunnel that once housed a violent river of molten lava. (To hear songs of native apapane, a crimson Hawaiian honeycreeper, keep quiet on your walk to the tube.) For those with four to five hours to spare, explore the East Rift Zone by traveling Chain of Craters Road, a 20-mile drive that descends 3,700 feet to the pounding coast. Along the way, pull over for a two-mile round-trip hike to Puu Loa Petroglyphs—an unforgettable site where ancient Hawaiians carved some 23,000 images into stone.

Travel Tip: Depending on conditions, the end of the road may offer a chance to see active lava flows.