Back in 1790, Hawaii got weird. Molten basalt from Kilauea surged through this part of the Puna district, wrapping wet 'ohi'a trees in thick, liquid rock. The inner wood burned completely away. What remains today at Lava Tree State Park are dozens of spooky, hollow stone chimneys standing tall in the jungle. Pretty wild, right As you walk the paved path, you are looking straight at the exact outer shell of ancient trunks that got flash-frozen in lava over two centuries ago.

Most folks stop by to stretch their legs on the easy 0.7-mile loop trail, but keep your eyes glued to the ground because deep earth fissures cut right past the concrete. Don't drop your keys down one. Thick moss, native orchids, and giant ferns have climbed all over these dark rock pillars, turning an old disaster zone into a damp, green wonderland. Nature moves fast out here. Actually, you can hit the whole park in under an hour, making it an easy, free pitstop on your way down to the Puna coast.