Lava Beds National Monument

Lava Beds National Monument, in northeastern California near the Oregon line, owes its rugged terrain to the Medicine Lake shield volcano, which has erupted repeatedly over the past half million years. It left behind more than 800 caves, lava tubes that drained as the molten rock cooled. Before you go underground, pick up a free caving permit at the visitor center; it also helps slow the spread of white-nose syndrome among bats. For each person, a helmet, a headlamp, and a handheld flashlight are recommended, plus long pants and sturdy shoes. Beginners start in the lit Mushpot Cave, then move on to Valentine or Skull Cave. Some caves are closed (as of October 2026).

The park's other story is the Modoc War of 1872-73: in Captain Jack's Stronghold, a maze of lava trenches, the Modoc held off the U.S. Army for about five months. Petroglyph Point holds thousands of rock carvings. There is no food service inside the park; stock up in Tulelake, about half an hour away. Plan at least half a day.