Craters of the Moon

Eighteen hundred square kilometres of black basalt in southern Idaho, erupted along the Great Rift as recently as 2,000 years ago, and so unearthly that Apollo astronauts were sent here in 1969 to learn volcanic geology before flying to the Moon. There are lava tubes you can walk into with a permit and a light, spatter cones, and cinder gardens where almost nothing grows. Shoshone tradition records the eruptions. PUBLIC national monument and preserve; caving needs a free white-nose-syndrome screening permit.