This is a glimpse through one of the windows in the wall of the Sun Temple, found in Mesa Verde National Park, Colorado. According to the National Park Service:
According to modern Pueblo Indians, Sun Temple’s features classify it as a ceremonial structure. Because neither household goods nor roof beams were found by archeologists at Sun Temple, some believe the symmetrically planned “D” shaped building was never completed. Yet its size alone points to the amount of labor that went into its construction. The stones in the fine masonry walls were shaped and given a “dimpled” flat surface by the builders of the structure. Based upon the amount of fallen stone removed during excavation, the walls probably were between 11 and 14 feet high. The thick walls were double coursed and filled with a rubble core. Today, modern concrete covers the top of the walls to prevent moisture from going into the rubble placed between the walls.