culture. After displaying severed heads, many scholars have determined that limbs of Aztec victims would be cannibalized Fray Diego Durán confirms this, stating that skulls were delivered to temples after "the flesh had been eaten". Durán notes that the were periodically renovated. Regarding this, Durán states When [the skulls] become old and deteriorated, they fell in pieces. When the palisade become old, however, it was renovated, and on its removal many [skulls] broke. Others were removed to make room for more, so that there would be a place for those were to be killed later Archeologist Eduardo Contreras believes that the tissue attached to skulls was removed prior to a pole being inserted through the side of the skulls. He bases these assumptions off of excavations of the Plaza de las Tres Culturas at Tlatelolco, Mexico City between 1960 and 1965. The was the central found in Tenochtitlan. The skull rack here served as a reminder of the Aztec's ongoing Flowery Wars. An important aspect of Aztec warfare was the capture of enemy warriors to serve as sacrificial victims, which is evident from the number of warriors found sacrificed around Aztec structures. One conquistador, Andrés de Tapia, was given the task of counting the skulls on the at Tenochtitlan and estimated that there were 136,000 skulls on it. However, based on numbers given by Taipa and Fray Diego Durán, Bernard Ortiz de Montellano has calculated that there were at most 60,000 skulls on the of Tenochtitlan. The consisted of a massive masonry platform composed of “thirty long steps” measuring fully 60 meters in length by 30 meters wide at its summit. Atop of the aforementioned platform was erected an equally formidable wooden palisade and scaffolding consisting of between 60 and 70 massive uprights or timbers woven together with an impressive constellation of horizontal cross beams upon which were suspended the tens of thousands of decapitated human heads once impaled thereon. Regarding this, Bernal Díaz de Castillo states: Various scholarly interpretations of the cosmological importance of 's placement have emerged. Eduardo Matos Moctezuma claims that a central was placed north of the Templo Mayor. Moctezuma notes that no corresponding shrine was found south. Moctezuma also notes that Mexica views of the universe, which divide the universe into a horizontal and vertical plane, claim that the northern sector of the horizontal plane corresponds to Mictlampa, or the land of the dead. On