Lava River Cave

Lava River Cave is a mile-long lava tube carved by an eruption roughly 700,000 years ago, tucked in the Coconino National Forest north of Flagstaff — and unlike most caves in the region, this one is open, unguided, and free to explore on your own schedule. With a 4.8 rating from over 1,800 Google reviews, it's become one of the most talked-about outdoor detours in the Flagstaff area, and the reviews make clear why people either love it or find it more than they bargained for.

What to expect

The path in is rugged from the start: reviewers describe loose rock, boulder-hopping, and a low, tight section early on that has some visitors crouching or nearly crawling depending on which fork they take (staying left is the common tip for avoiding the lowest squeeze). It's pitch black once you're past the entrance — multiple reviewers stress bringing several independent light sources, since a dead flashlight down there is a real problem. Expect cold temperatures year-round, good hiking boots, and a round trip that typically runs one to three hours depending on pace and how far you go.

Good to know

• Access: reached via an unpaved forest road — a vehicle that can handle a bumpy dirt drive is recommended
• Hours: the site itself is open 24 hours, with no gate or staff on-site
• Bring: multiple headlamps or flashlights, sturdy footwear, and layers for the cold

It's a genuine adventure rather than a casual stroll, but families with older kids and well-prepared hikers consistently rate it among the best free outdoor stops near Flagstaff.