Why Build a City on a Mountain?

Why was the city of Calixtlahuaca (3 square km of occupation, probably 10,000+ inhabitants) built on a mountain? Most Mesoamerican cities built on mountains (think of Monte Alban or Xochicalco) were placed there for reasons of defense. Images of mountaintop cities in Mesoamerican codices (see my earlier blog entry on these) tend to show battles and defensive walls. But for several reasons, we don't think that defense was a major factor in the layout of Calixtlahuaca:

1. We did not find any defensive walls or ditches.
2. The largest civic buildings were not built in a protected location.

The second factor is quite striking. The royal palace was at the base of the hill, completley unprotected, as was a large unexcavated platform (a possible ballcourt). The two largest temples, structure 3 (circular temple, dedicated to Ehecatl) and structure 4 (rectangular temple, dedicated to Tlaloc) were built part-way up the hill, but closer to the base. Again, these were relatively unprotected. When defense is an issue, the main civic buildings are almost always built at the top of the mountain or hill (again, think Monte Alban or Xochicalco).

Well, what is so surprising about building a city on a mountain if defense was NOT a major consideration? The answer is the effort required to build the site. Every house that was built had to be accompanied by the construction (and constant maintenance) of stone terraces. Temples 3 and 4 required massive platforms and large excavations into the hillside to build level areas for these temples and their groups.

I have some hunches about why Calixtlahuaca may have been built on a mountain, but I will refrain from saying them now. One thing I am doing is looking for other ancient cities around the world whose residential zones were built on mountainsides, with the civic architecture at the base of the hill. Ephesis (the Roman occupation) is one example (see photo), and I am looking for others. If you have suggestions, let me know.

Project update

Sorry, the blog has not been active lately. Well, we will soon have a bunch of new posts, so stay tuned. I have been very busy with several things:

(1) A trip to France and Sweden. In Paris, I participated in the the doctoral dissertation hearing of project member Maëlle Serghereaert at the Université de paris I-Sorbonne-Panthéon. Maëlle passed at the highest level. Here she is drawing stone on structure 4:Here is her thesis, a truly excellent study of the organization of the Aztec emire:

Serghereaert, Maëlle
2009 L'expansion mexica (1430-1520 après J.-C.): La question du contrôle impérial dans les provinces extérieures de l'Empire. Ph.D. dissertation, Department of Archaeology, Université Paris 1, Panthéon-Sorbonne.

In Paris, I also gave a lecture on the Calixtlahuaca project, and Cindy and I also found time for museums, medieval churches, and pastries.

(2) I was working on our final report for the National Science Foundation for the first grant (funding for the fieldwork). This is now submitted, and we can get on to publications and a report for the Mexican government.

(3) Here is a positive development. This blog has been an inspiration for a new blog on excavations at Xaltocan in the Basin of Mexico. Lisa Overholtzer, a graduate student of Elizabeth Brumfiel at Northwestern University, as started a blog on her current excavations of Aztec-period houses at Xaltocan. These are important excavations, and it is a very nice blog. Please check it out!