Sunset Crater Volcano National Monument

Just north of Flagstaff, an extinct volcano cone and a lava-trail hike are beautiful yet eerie reminders of the brutal forces of nature.

Why go: Some 900 years ago, a volcanic eruption spewed lava and ash that spread for miles and formed the red cinder cone known as Sunset Crater. It's perhaps the most recognizable of the 600 or so cinder cones around Flagstaff.

Don’t miss: The easy, 1-mile Lava Flow Trail winds through the jagged landscape of the Bonita Lava Flow. A quarter of the trail is paved and wheelchair-accessible. With the San Francisco Peaks as a backdrop, you can follow the trail and imagine what the eruption may have been like. The hardened black lava is rough and sharp. Wear sturdy shoes and mind where you put your hands.

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Insider tip: You can’t hike up Sunset Crater, but you can make the steep, half-mile trek up the cinder-covered Lenox Crater for good views of Sunset Crater, the lava flow and the San Francisco Peaks. In summer, rangers lead hikes here and along the Lava Flow Trail.

Along the way: If you want to go inside an extinct volcano cone, venture about 30 miles north of Flagstaff on U.S. 180 to Red Mountain. After an easy, 1.5-mile walk along a wash and a climb up a short ladder, you're inside a U-shaped amphitheater that's believed to have formed 740,000 years ago. Think about that while you're walking among the hoodoos and crevices.

Getting there: About 170 miles north of Phoenix.

Details:www.nps.gov/sucr.