Open Ceiling Cave on Na Pali Coast, Kauai, Hawaii, USA. This cave is a hollowed-out lava tube, and may have served as a place where ancient Hawaiians could rest in their canoes when traveling along the coast.
Hawaii is on a lot of people's travel bucket list. You may think sand beaches and volcanoes, but formations like this are breathtaking. What's your favorite thing about Hawaii? (Na Pali Coast Waterfall Cave, Hawaii)