Tsin Kletsin is an Ancestral Puebloan great house atop South Mesa in Chaco Culture National Historical Park, south of Pueblo Bonito in a relatively isolated setting. Built around A.D. 1110 to 1115 during the late Chaco era, it originally included 81 rooms, 3 kivas, and a plaza within a two-story complex. Its enclosed plaza opened through a narrow southern portal, and its masonry reflects the McElmo or Chaco-McElmo style. Nearby Weritos Dam may have collected storm runoff to supply the settlement’s domestic water, though maintaining that reservoir would have required repeated rebuilding, dredging, and recovery from flooding.