Kaūmana Drive, Hilo, Big Island, Hawaii
If you’re up for exploring these lava tube caves, then make sure to pack some heavy duty flashlights (no, your smartphone flashlight app will NOT do), shoes with good traction, some light outerwear (it can get cool underneath) and your sense of wonder. The Kaumana Caves attract adventurous, non-claustrophobic types from all over who aren’t afraid to get on their hands and knees to squeeze through the narrower portions of these pitch black natural tunnels for some exciting subterranean exploration. If you happen to fit into this category, make sure to bring two flashlights just in case one fails! You’ll be rewarded with a view of underground caverns adorned with centuries-old “graffiti” and gorgeous stalactite formations.