Canyon de Chelly, the second largest Canyon in the USA, features towering sandstone cliffs, prehistoric rock art and the remains of ancient Pueblo villages. White House Ruins, an 80-room settlement is scenically situated beneath a graceful, slightly overhanging cliff streaked with desert varnish. The hike down to these ruins zigzags down the flank of the canyon about a mile, descending 1000 feet. It is the only area visitors are allowed to hike int the canyon. The archaic petroglyph below the White House dates from 2500–200 BC.