The Site of Izapa

Izapa is a large Formative site located in the far southeastern corner of the State of Chiapas, Mexico,
immediately adjacent to the Guatemalan border. It was once the thriving cultural and commercial
center of a rich agricultural region called Soconusco which extended along the Pacific coastal plain
from the area around present-day Tonalá, Mexico in the north to about San José, Guatemala in the
south. Among the early exports of the region were cacao, quetzal feathers, and rubber. The nearest
modern city is Tapachula, some 10 km (6 miles) to the west. The geographic coordinates of the site
are latitude 14.8 º N. and longitude 92.2 º W.

In 1973, when I made my first field trip to Mexico and formulated my hypothesis of calendrical
origins which was published in Science in early September of that year, there were three clues
which prompted me to select Izapa as the "place where time began" in Mesoamerica: (1) Astronom-
ically, it lay at the only latitude in North America where a 260-day interval (the length of the
"strange" sacred almanac used throughout the region in pre-Columbian times) can be measured
between vertical sun positions -- an interval which happens to begin on the13th of August -- the day
the peoples of the Mesoamerica believed that the present world was created; (2) Historically, it was
the only site at this latitude which was old enough to have been the cradle of the sacred almanac,
which at that time (1973) was thought to date to the 4th or 5th centuries B.C.; and (3) Geographically,
it was the only site along the required parallel of latitude that lay in a tropical lowland ecological
niche where such creatures as alligators, monkeys, and iguanas were native -- all of which were
used as day-names in the sacred almanac.


The zenithal passage of the noon-day sun over Izapa may have been measured by no more sophisticated a "gnomon" than such a stone column as this, near the main pyramid of Group F at Izapa. The date on which the sacred almanac was initiated appears to have been August 13, 1359 B.C.

The cone of Volcán Tajumulco, the highest mountain in Central America, marks the sunrise position at the summer solstice (June 22) as seen from Izapa -- the day in 1325 B.C. when the 365-day secular calendar most likely was set in motion.

My first visit to Izapa was made the following year (1974), at which time I discovered that not
only could the sacred almanac be calibrated at the passage of the zenithal sun but that the 365-day
secular calendar could also be calibrated from the same site by reference to the highest volcano in
all of Central America. Although I first noted that the entire ceremonial center was oriented to the
Volcán Tacaná (4093 m, or 13,425 ft.-- the mountain shown in the photo at the top of this page),
I was struck by the fact that the yet-higher Volcán Tajumulco (4220 m, or 13,842 ft.) was also
clearly visible on the north-eastern horizon. The question of why the site had not been oriented to
the higher mountain prompted me to investigate its azimuth (i.e., its angular compass direction) as
seen from the main pyramid. When I determined that this was 65º, I realized that the highest
volcano in all of Central America had been used to mark the sunrise position on the summer
solstice (June 22) -- thus establishing the true length of the solar year.

Subsequent field work and map investigation revealed that more than thirty of Mesoamerica's
most ancient and important ceremonial centers were likewise solsticially oriented to the highest
mountain within view. That many of these were located at distances well in excess of the 30 km
(18 miles) that separated Izapa from Tajumulco strongly suggests that a "principle" first established
in the far south of present-day Mexico had diffused with the calendar into the core of Mesoamerica
as time went on. That one of these was San Lorenzo, the oldest of the "Olmec" ceremonial centers
in the Gulf Coastal Plain of Mexico (dating to 1200 B.C.) strongly supports my computer-assisted
investigation of the calendars' age which places the origin of both the secular and sacred counts
back in the fourteenth century B.C.

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