1888-1891. Close-up of vaulted rooms in east side of temple, as seen in photo above; showing a variety of differently shaped facing stones, tenoned into concrete rubble core.       
1888-1891 photograph by Henry N. Sweet as a member of the Thompson/Peabody expedition; scanned from 35mm slide of original photograph at Dumbarton Oaks. Reproduced Courtesy of the Peabody Museum of Archaeology and Ethnology, Harvard University.