Have you ever walked through a lava tube? At the Hawai’i Volcanoes National Park on the island of Hawai’i, you’ll be able to experience this unique hike. The Thurston lava tube is a 500-year old lava cave formed when an underground channel of molten lava drained from its cooled walls forming a massive, hollow chamber. A tropical rainforest awaits you at the end of the tube.