Kazumura Cave is a lava tube and has been surveyed at 40.7 miles ( 65.5 km ) long and 3,614 feet ( 1,102 m ) deep making it the longest and deepest lava tube in the world . The cave is located on the island of Hawaiʻi on the eastern slope of Kīlauea . Kīlauea is the most recently active volcano on the Big Island . The ʻAilāʻau lava flow that contains Kazumura Cave originated from the Kīlauea Iki Crater about 500 years ago
ʻAilāʻau
ʻAilāʻau eruption
Kazumura Cave