Nov. 23 (Bloomberg) -- It’s one of the most mysterious places on earth.

We don’t know who built it nor why they abandoned it around 750 A.D.: The Aztecs, who occupied the site seven centuries later, called it “City of the Gods.”

An exhibition at the Musee du Quai Branly in Paris brings us up to date on the latest research.

Archaeologists previously thought that Teotihuacan, once the largest metropolis in pre-Columbian America and today a vast field of ruins 25 miles northeast of Mexico City, had been a peaceful theocracy. Recent excavations have forced them to correct that misconception: Human sacrifices were part and parcel of the rituals.

Some of the skeletons found beneath the pyramids had been beheaded; others had their hands tied behind their back. Most of them were buried with pumas, rattlesnakes and other animals, which has led scholars to believe that animals played an important role in the religion of the community.

Shell necklaces adorning several skeletons have been interpreted as military insignia: The victims, anthropologists suspect, were prisoners of war.

All this is little more than educated guesswork. In the absence of written records, nothing can be said for certain.

Feathered Serpent

Nor do we know who Teotihuacan’s rulers and high priests were. The names usually given to the mythological figures portrayed by sculptures and murals, such as Quetzalcoatl, the Feathered Serpent, or Tlaloc, the Rain God, are those of Aztec deities. It would be wrong, though, to dismiss the city’s founders as bloodthirsty cavemen.

The most striking aspect of the site is its geometrical design, an urban grid with the “Avenue of the Dead” as the central axis. It’s flanked by pyramids, temples and apartment compounds of high quality.

With maps and models, the organizers do their best to give you an idea of the vast site. Solid chunks of murals have been shipped to Paris to demonstrate the richness of the city’s interiors. Some of the fantastic creatures on the walls are worthy of a painting by Hieronymus Bosch.

The sculptures and ceramics are no less fascinating. Terra cotta figurines with the most outlandish hairstyles and headgears, salamanders designed to hold coals and keep food warm, tripod vessels bearing the face of the Rain God or vases in the form of a sleeping dog -- the imagination of the artists knew no bounds.

Designer Duck

The tallest sculpture found in Teotihuacan portrays a prisoner who has been executed with arrows. Another, less gory, specimen is a pot nicknamed “Pato Loco” (Mad Duck), which looks more like an overdressed dragon.

The most beautiful of the 450 items may well be the stone masks that were sewn onto the funerary shrouds to symbolize the face of the deceased. The eyes and the mouth are incrusted with shell, obsidian or turquoise, giving them a remarkably vivid expression.

Obsidian, a hard rock that looks like glass, also was used for making jewelry, blades, knives and arrowheads. Some scholars believe that the obsidian monopoly -- metal tools and weapons being unknown -- was the basis for Teotihuacan’s domination of central Mexico.

That may or may not be true. Since only five percent of the site has been explored, there may still be surprises.

“As long as we haven’t found a trace of a ruler in his palace,” the Mexican anthropologist Miguel Baez Perez told the Paris daily Le Monde, “we have no idea what Teotihuacan was all about.”

“Teotihuacan: Cite des Dieux” is at the Musee du Quai Branly, Paris, through Jan. 24, 2010. The exhibition is sponsored by Grupo Televisa SA’s Fundacion Televisa. For details, see http://www.quaibranly.fr or call +33-1-5661-7000.

(Jorg von Uthmann is a critic for Bloomberg News. The opinions expressed are his own.)

To contact the writer on the story: Jorg von Uthmann in Paris at uthmann@wanadoo.fr.

Last Updated: November 22, 2009 19:00 EST