San Pablo Villa de Mitla, Mexico

The town of MITLA ("Place of the Dead"), where the bus from Oaxaca finally drops you, is some 4km off the main road and just ten minutes' walk from the site of the famous ruins. It's a dusty little place where you'll be harassed by would-be guides and handicraft vendors (there's also a distinctly second-rate crafts market by the ruins). Accommodation can be found at the Hotel Mitla (Tel:951/568-0112; Price: M$200–350), or La Zapoteca (Tel:951/568-0026; Price: M$200-250), in town on the way to the ruins. Restaurant Don Cenobio (Tel:951/568-0330), located in the hotel of the same name, is the most stylish place to try local Oaxacan specialities at reasonable prices. On the main square, the hotel has a relaxing courtyard and thoughtfully appointed, spotless rooms (Price: M$500-750).

Mitla reached its apogee during the post-Classic period, when Monte Albán was in decline. Construction at the site continued up until the late fifteenth century, at which point it was finally conquered by the Aztecs. The abstract designs on the buildings seem to echo patterns on surviving Mixtec manuscripts, and have long been viewed as purely Mixtec in style. But more recent opinion is that the buildings were built by Zapotecs and that the city was a ceremonial centre occupied by the most important Zapotec high priest. This Uija-Tao, or "great seer", was described by Alonso Canesco, a fifteenth-century Spaniard, as being "rather like our Pope", and his presence here would have made Mitla a kind of Vatican City.

While the site itself (daily 8am–6pm; M$30, free on Sun) may not have the grandiose scale and setting of MonteAlbán, Mitla impresses with its superlative bas-reliefs and geometric designs, You'll see it at its best if you arrive towards closing time, when the low sun throws the patterns into sharp, shadowed relief, and the bulk of the visitors have left.

There are four main palace complexes here, each magnificently decorated with elaborate stone mosaics that are considered peerless throughout Mexico. The Grupo de las Columnas is the best preserved and most impressive of these, and the obvious place to head for from the entrance. The only other sites that the long, low buildings recall in any way are the two post-Classic sites of El Tajín and Uxmal, which, along with other evidence, suggests that there may have been some contact between these most influential groups.

The first large courtyard in the Grupo de las Columnas is flanked by constructions on three sides – its central Templo de las Columnas is magnificent, precision-engineered and quite overpowering in effect. Climbing the broad stairway and through one of three entrances in its great facade, you come to the Salón de las Columnas, named after the six monolithic, tapered columns of volcanic stone that supported its roof. A low, narrow passageway leads from here into the small inner patio (Patio de las Grecas), lined with some of the most intricately assembled of the geometric mosaics; each of the fourteen different designs here are considered representative of the universe and the gods. Four dark rooms that open off the patio continue the mosaic theme. It is in these rooms that the Uija-Tao would have lived. If the latest theory is correct, the Zapotec architects converted the inner room of the traditional Mesoamerican temple, in which priests usually lived, into a kind of exquisitely decorated "papal flat" arranged around a private courtyard. The second courtyard of the Columns group, adjoining the southwestern corner of the first, is similar in design though less impressive in execution. Known as the Patio de las Tumbas, it does contain two cross-shaped tombs, long since plundered by grave-robbers. In one, the roof is supported by the Columna de la Muerte; legend has it that if you embrace this, the gap left between your hands tells you how long you have left to live: hand-widths translate into years remaining. At the time of writing, the column could no longer be embraced; officials at the site could not say if this is a permanent arrangement.

The Grupo de la Iglesia, a short distance north, is so called because the Spanish built a church over, and from, much of it. Two of its three original courtyards survive, however, and in the smaller one the mosaic decoration bears traces of the original paint, indicating that the patterns were once picked out in white from a dark-red background.