Crater Rings is a broad shield volcano in Idaho’s Western Snake River Plain, about eight miles northwest of Mountain Home, topped by two strikingly symmetrical pit craters that are among the few such examples in the continental United States. The eastern crater measures about 3,000 feet across and 350 feet deep, and the western crater about 2,500 feet across and 300 feet deep. Geologists believe the craters were probably once lava lakes similar in form to Halemaʻumaʻu at Kīlauea in Hawaii. Considered the youngest nearby shield volcano, it is estimated to be less than two million years old and was recognized as a National Natural Landmark in 1980.