More than eight centuries ago, this hilltop was the site of an important ancient Pueblo Indian community in the Bluff valley. Built by AD 1100 and abandoned about AD 1300, the Bluff Great House was a large sandstone structure made from cliffs behind the site, with two rows of rooms, high ceilings, two stories along the rear row, one story along the front row, and three round kivas built into the front row. Although erosion reduced it to a mound of sandstone rubble, its buried stone walls survive and its floors remain at the same level as the surrounding ground. The great house was encircled by a low earth berm whose purpose remains uncertain, perhaps marking a symbolic boundary rather than serving as defense. Southwest of the great house stood a great kiva, a huge round masonry-walled room with a massive roof supported by four thick posts and attached rooms at the north, south, east, and west, probably used for community ceremonies by families living in smaller houses along the San Juan River and nearby creeks. The site lay within the civilization created by the ancient ancestors of today's Pueblo Indians in New Mexico and Arizona, and at the edge of the region centered on Chaco Canyon, where broad engineered roads linked distant communities. Large villages existed in the Bluff area as early as AD 700, and several roads were built around the Bluff Great House, including one leading north to other nearby sites and another pointing southeast, suggesting a possible connection with Chaco Canyon.