Haleakala Cinder Cones
The interior of Haleakala crater is littered with these cinder cones, some of which are a couple hundred or more feet tall. I particularly enjoy their color and texture, as it's so unlike anything else near our home on the coast.
You can see walking trails in these images, which traverse around and through the giant crater itself. In one image, there's a small cabin, about 10mi out from the trailhead. The cabins are part of the national park backcountry permitting / camping system, and are available by reservation only.