Dating from the early 1100s, North America's largest reconstructed Great Kiva (a partially submerged, circular earthen structure used for ceremonial and community-wide activities) and a pueblo dwelling that once contained more than 500 rooms, Aztec Ruins National Monument and Museum, makes for a rewarding stop. The ruins have been designated a World Heritage Site because of their significance in what is known as the Chaco Phenomenon, the extensive multitribal social and economic system that reached far beyond Chaco Canyon. This pueblo was abandoned by the mid-1200s. Early homesteaders thought they'd come across an ancient Aztec ruin, hence the odd name. You only need an hour or so to tour the ruin, which is less spectacular but considerably more accessible than those at Chaco.
Ruins Rd., ½ mi north of NM 516, Aztec, 87410, USA