Crater Rings is a striking geologic curiosity on the high desert plains near Mountain Home, Idaho — a pair of large, remarkably symmetrical pit craters that count among the few good examples of their kind in the continental United States. Designated a National Natural Landmark, this quiet, lesser-known spot offers a fascinating window into the volcanic forces that shaped the Snake River Plain.

Unlike the explosive cinder cones most people picture, these two adjacent craters are pit craters — formed not by an eruption blasting outward, but by the ground collapsing as an underground column of lava rose and then drained away, leaving deep, round, steep-walled pits behind. The result is a pair of dramatic bowls sunk into the desert, a geologist's delight and an intriguing destination for the curious.

This is an undeveloped, out-of-the-way site on public land, so come prepared and tread carefully. There are no facilities, and the crater rims are steep and unfenced — stay well back from the loose edges, keep a close eye on children, and don't attempt to climb into the pits. Adventurous visitors come to hike the rims and take in the views, and the rocky terrain even draws the occasional climber.

The high-desert setting is best visited in the milder months of spring and fall, since summer can be blazing hot and exposed. Bring plenty of water, sun protection, and sturdy shoes, watch your footing near the rims, and pack out everything you bring in. For travelers with a taste for geology and offbeat natural wonders, Crater Rings is a uniquely Idaho stop.