XOCHICALCO

Xochicalco, which means "In the place of the House of the Flowers", lies atop an array of low-lying hills, the main ones of which are known as La Bodega, La Malinche, and Xochicalco. The site was laid out and built in accordance with a carefully contrived urbanization plan. The summit of Xochicalco hill was graded so as to facilitate the construction of the main buildings, and the slopes, too, were altered to provide room for homes and terraces to prevent easy access to the site. Xochicalco reached its height as one of the great cities of Meso-America in Late Classic times (AD 650-900). Most of the monumental architecture now visible was constructed during that period. I think this could be considered one of the most beautiful cities in the world at the time it was constructed. It is a very well thought out design of terraces, streets, plazas and buildings. And located on the top of the mountain there is a fantastic view in every direction.

The rise and development of Xochicalco is best understood in its relation to Teotihuacan, the dominant urban center in Meso-America throughout the Classic Period. According to some researchers, Xochicalco must have risen following the abandonment of that center of the central plateau in order to fill in the economic and political power vacuum created by the decline.
The distribution of Xochicalco followed a hierarchical order; on the peak, surrounded by barriers, is the Acropolis, a residential area for the leaders and their families. At the Main Plaza is the Pyramid of the Feathered Snakes and other buildings, where the political, economic and religious goals of the city were decided. On a lower terrace is the Great Pyramid, where religious ceremonies took place.
One of the most outstanding constructions of Xochicalco, is the the temple of Quetzalcoatl, widely recognized by his refined high - relieves wich represent different symbols and passages from this God, symbolized by the effigy of the feathered snake.
The Pyramid of the Feathered Snakes has beautiful sculpted relieves, representing eight huge feathered snakes embellished with great headpieces, snails, important leaders and the new fire symbol. On the panel there is a series of persons holding a bag that represents the symbol for speech and a disc divided into four, possibly representing a solar eclipse, phenomenon visible from Xochicalco in 743 A.D.
In 1963 remains were found of two substructures built previously to those visible today, as well as of ferings and burials. The main motif depicts Quetzalcoatl as the plumed serpent. It is to be noted that the wooden beams of the stairway look like the ventral scales of a snake's body. The rest of the decorative elements are related to personages, cylindrical signs, and places. On the upper part there are, between the undulations of the serpent, several human figures, some with the slash denoting the spoken word. The may represent priests or great chieftains. In combination with these dignitaries can be seen the sign for fire together with a date (symbolized by one bar and four dots). On the sides, above this first body, there are reproductions of priests with their calendar names. On the upper part of the structure are found human figures identifiable as warriors because some wear helmets and feathered headdress and hold atlatl, that is, lance throwers. These figures are shown with place symbols and their names. On the left of the staircase there is a remarkable carving which shows sign 5 calli, "house", being joined with sign 11 ozomatli, "monkey", by a personage standing behind and pulling "monkey" with a rope. This has been interpreted as a calendar correction or adjustment. Thus the most common idea as to the function of the structure is that it commemorates a meeting of priests and great chieftains for the adjustment of the Meso-American calendar, although the monument may have other meanings..
Archaeologists state there was an astronomer recording the sunrise every day, for many generations, in order to observe the sun’s dynamic, thus establishing climate patterns according to the stars. It was the venue for a gathering of priests from all Mesoamerican cultures that made an adjustment to the calendar. This event was recorded on the Pyramid of Quetzalcoatl.

The plaza faces the sunset, marking equinoxes and solstices because the inhabitants of Xochicalco depended on agriculture. This issue led them to develop a very precise system for establishing the cycles of the sun, moon, planets and stars in a ritual revolving around the agricultural calendar. Every March 21 at sunrise, the sun shines exactly through the middle of a sculpture, aligning with an inscription and the central monument.
Estructura A. Around a court yard at its top there are two halls and the Temple of the Steles, so called because of three steles found in a stone encasement beneath the flooring. These steles are now on display at the National Museum of Anthropology. They are carved in low relief and exhibit remains of red or vermilion paint. They narrate various events related to Quetzalcoatl such as the Venusian cycle, wherein Venus is transformed into Quetzalcoatl, who represents this god as the lord of time with respect to his invention of the calendar, as well as to his creation of the Fifth Sun in Teotihuacan and his discovery of maize (corn).
The Chamber of Offerings. This is a small building next to Structure A. It contains a single room or chamber in which an offering consisting of two smooth stone yokes related to the cultures of central Veracruz were found together with and anthropomorthic ax and a stone tablet with the hieroglyphs 5 or 10 acatl and 4 tochtli. These findings, as well as the Mayan and Zapotec glyphs uncovered in the Pyramid of the Plumed Serpent, have been interpreted as evidence of close contacts between Xochicalco and distant areas. Ball Court. This is one of the two buildings of this type excavated in the zone (the other, less elaborated, is located on the north side of the Ceremonial Plaza). Because of the size, shape, layout, and other features, it has been compared with several others in Mayan area

The cave is an astronomical observatory, used to recognize the beginning of the agricultural cycle. Originally, it was covered in stucco painted in black, yellow and red. Its observation chimney precisely projects sunlight and during the night, it allows a perfect view of the stars. Two of the many natural underground caves at Xochicalco, show clear evidence of architectural modification, including the perforation of an artificial hole or "chimney" from the cave to the ground above. These vertical shafts would have enabled very precise observations and measurements of solar and possibly planetary events. For instance, the vertical north side of the 5-meter-long "chimney" down into one cave would have resulted in a precisely vertical beam of sunlight on the day of the zenith. The south side of the chimney slopes at an angle of 4o23'. Is it simply a coincidence that this is the exact angle for light to be parallel to this side on June 21, the day of the Summer solstice? Archeo-astronomers think not!

The dimensions and geometry of this chimney ensure that some light enters the cave every day from April 30 (15 days before the first of the two annual zeniths) to August 12 (15 days after the second). Put another way, the cave receives light every day from precisely 52 days before the solstice to 52 days after it. The number 52 was of immense significance in the pre-Columbian calendar, since it took exactly 52 (solar) years for both the solar calendar and the ritual calendar (of 260 days each) to return simultaneously to the equivalent of 0-0.

Another fascinating finding, first published in México Desconocido, is that from the "Acropolis" of the site, on zenith days, the sun rises exactly behind Popocatépetl volcano on the eastern horizon. The effect does not occur even one day before or after the zenith. Given the polluted skies over Mexico City, it is difficult to guarantee witnessing this effect nowadays!

The site of Xochicalco is living proof of one of the most important scientific summits ever held in the history of the Americas. The congress of astronomers from all over the zone held to agree the calendric correction was a landmark event in the history of science worldwide.

Xochicalco is a fascinating place to wander around. Let your imagination wander. Imagine the astronomers and their cohorts engaged in deep philosophical discussions.