Following a volcanic eruption, underground lava tubes serve as thoroughfares for draining molten lava. When the lava cools and remaining flows drain out of the tubes, the subterranean passageways remain, leaving behind caves to explore. There are several spots in the United States to see lava tubes, including Lava Beds National Monument in northern California, …
Continue reading Caves Trail (Craters of the Moon National Monument, ID)

