Amboy Crater National Landmark is a great example of a dormant volcanic cone. North of the crater, off Route 66, there is a short path dotted with black volcanic rocks that in the summer is often covered with yellow wildflowers that leads to the western slope of the crater. The path then leads up the slope and into the crater, where hikers can walk around the perimeter and look out at the vast expanse of desert (and the tiny outpost of Amboy to the northeast) for miles. It’s about 4 miles from the parking lot to the crater and back.
Make sure to visit the town after your hike… The little general store has frozen candy bars and milkshakes, and the abandoned resort is worth a look.