Black Canyon of the Gunnison National Park

A narrow, deep canyon carved by the Gunnison River through some of the oldest exposed rock in North America, with walls of dark Precambrian gneiss and schite rising up to 2,722 feet. The canyon's narrowness — as little as 40 feet at river level — means the sun penetrates to the bottom for only a short window each day. The South Rim Drive follows the canyon edge with 12 overlooks, including Painted Wall, the tallest cliff in Colorado. Inner canyon routes are unmaintained and require a free wilderness permit.