Built in the 13th century, the 14½-acre Casa Malpais Archaeological Park pueblo complex has a series of narrow terraces lining eroded edges of basalt (hardened lava flow) cliff, as well as an extensive system of subterranean rooms nestled within Earth's fissures underneath. Strategically designed gateways in the walls of the "House of the Badlands," as Spanish settlers called it, allow streams of sunlight to illuminate significant petroglyphs prior to the setting equinox or solstice sun. Casa Malpais's Great Kiva (any kiva over 30 feet is considered great) is square-cornered instead of round, consistent with Ancestral Puebloan practice. Some archaeologists believe the pueblo served as a regional ceremonial center for the Mogollon people. Both the Hopi and Zuni tribes trace their history to Casa Malpais. Start your visit at the Springerville Heritage Center, home of the Casa Malpais Museum. Two-hour tours leave at 9, 11, and 2.