Posted on

The Dry Stone Work of Mitla Archeological Site in Oaxaca, Mexico

Many thanks to Tom Kirschner for contributing this article.

A few weeks ago my wife and I reluctantly returned from a Road Scholar trip to the southern Mexican state of Oaxaca.  Our trip was cut short and we didn’t want to leave.  It was clean, safe, and the food and climate are delightful.  The people are warm and welcoming.  Oaxaca City is a three-hour flight from Dallas. It is located along the narrow land bridge between North and South America, between the Gulf of Mexico and the Pacific Ocean. We visited an archaeological site called Mitla where the dry-stacked stonework is amazing. When I showed some pictures to Brian Post he was equally impressed and asked that I share it with you.

Mitla dates from about 500 BC, and its construction as a ceremonial center began in 850.  It was active until 1520, when the Spanish arrived.  They destroyed much of it and used the stones to build the Church of San Pablo, which sits on top of part of the ruins.   The many volcanic caves in the surrounding hills are a UNESCO site because of the fabulous pictographs carved into their walls.  Local guides can take you there. In these caves scientists have discovered the oldest cultivated crops in North America, dating back 10,000 years. They found the seeds of corn, beans, squash, chilies and hallucinogenic drugs, all of which were important to Mesoamerican civilization. Mitla is a one- hour drive from Oaxaca City and is located on the outskirts of a town of 15,000 residents called San Pablo Villa de Mitla.

Mitla was built during the time of Zapotec rule and was later occupied by the Mixtecs.  Their ancestors live in the region to this day and many still retain their original dialects and customs.  The name Mitla is a Spanish version of the words “Mictlan” which means “Place of the Dead” or “Hell”. It was built as a gateway between the world of the living and the world of the dead.  A Spanish Friar wrote in 1520 that the high priest (called the Uija Tao) lived here.  He likened him to the Catholic Pope and no one dared look at or speak to him.  He ruled from a throne covered with jaguar skins.  He used the same type of hallucinogenic drugs found in the caves (psilocybin mushrooms, Jimson weed, peyote, morning glory seeds, and the skin of poisonous frogs) to enter a trance and perform ceremonies and human sacrifice.  The walls of the four chambers that he lived in are covered with exquisite stone carvings and the designs are pressure fit without mortar.  Today these same designs are repeated in the hand-woven rugs and textiles of the region. The hard volcanic stone was shaped without metal tools and each piece is as precise as if it were cast in a mold. No other site in Mexico, or indeed the world, has this. The Spanish were so astonished they left it untouched.

Mitla has underground chambers were important Zapotec rulers and priests are buried. I had the opportunity to explore one such vault and descended the eight stone steps that projected out from a wall to the entrance.   I had to crawl the first fifteen feet and then I was able to stand up.  The air was dank and stale and a single electric bulb hung from the ceiling. No one else was inside with me. To be perfectly honest I didn’t pay much attention to the razor- straight stone blocks around me.  Suddenly I felt a jolt of panic and claustrophobia and scurried as quickly as I could back toward the shaft of sunlight and fresh air, banging my head on the ceiling on the way out.  It was not until later that I learned how over the centuries untold numbers of captives had been sealed inside this same chamber as living sacrifices.

Climbing up twenty or so very steep steps takes you to an impressive courtyard called the Hall of the Columns.  Six pillars, each of them twelve feet high and weighing eighteen tons, are arranged in a line.  They are precisely carved and are not cylinders but instead have a constant curve throughout. Our guide said the stone was shaped using crushed obsidian, a volcanic glass, but I found this explanation unsatisfactory: obsidian is a softer stone than the volcanic trachyte.  On the Mohs scale of hardness trachyte is 6 and obsidian is 5.  There are also no close sources of obsidian: it was a trade good that was carried in from far away.  Each column originally weighed about 25 tons uncarved, and I saw a broken block of about this weight lying in a courtyard.  The quarry was located on a mountain fifteen miles away and these blocks were moved without using horses, donkeys, roads, or the wheel.

Obsidian was used to shape into arrowheads and knives that were even sharper than today’s surgical scalpels. It was far too valuable to be used as sandpaper. The devil is in the details.

As stonemasons we understand better than most how difficult stone can be to work with.  And we have the advantage of using carbide chisels, Makita grinders, Stihl cut- off saws and heavy equipment.  From my own experience I could not fathom how these columns could be shaped with stone tools.

I suggested to a retired archaeologist who was with us that it would be interesting to use lasers to measure the circumference of each column individually and collectively at different heights to determine the degree of accuracy. She was intrigued and may pass this along.

Stonework makes a great archaeological marker because it withstands the ravages of time so well.  What remains at Mitla is incredible and difficult to explain.  It is a bit of “un milagro”, a miracle, and that is something we need right now. When all of this is over, I would encourage everyone to visit Oaxaca and Mitla to experience this first hand.