Some of the best views of volcanic activity in extreme Northern California lie within Lava Beds National Monument (Hill Rd., www.nps.gov/labe, Memorial Day–Labor Day daily 8 a.m.–6 p.m., Labor Day–Memorial Day daily 8:30 a.m.–5 p.m.). Over hundreds of millennia, the Medicine Lake shield volcano has created an amazing landscape.

In amongst the Modoc battle sites, campgrounds, and desertlike wilderness, you’ll find numerous caves created by ancient lava tubes. Some of these have been developed with ladders and walkways, others remain in their original difficult-to-explore state. But they’re worth your time and energy, even if you’re not usually a spelunker.

Not all of the lava tubes have remained empty for all these years; some have become home to whole ecosystems that thrive in the dark and the damp. Bring a flashlight, but be kind to the bats that dwell in these caves while you’re checking out the ferns, mineral formations, and other unique features.

Whether you’ve been into volcanoes in the past or not, the Lava Beds stand a good chance of winning you over.