Second only to Monte Albán in their importance, though not as old, the ruins of ancient Mitla date from the final two or three centuries before the Spanish conquest in the 1520s, and comprise what was probably the most important Zapotec religious center at the time – a cult center dominated by high priests who performed literally heart-wrenching human sacrifices.
The geometric ‘mosaics’ of ancient Mitla have no peers in ancient Mexico: the 14 different designs are thought to symbolize the sky and earth, a feathered serpent and other important beings, in sophisticated stylized forms. Each little piece of stone was cut to fit the design, then set in mortar on the walls and painted. Many Mitla buildings were also adorned with painted friezes.
Mitla's ancient buildings are thought to have been reserved for specific occupants: one group for the high priest, one for the king and so forth. Visitors usually just see the two main groups in the town: the Grupo de las Columnas (Group of the Columns) in front of the three-domed Iglesia de San Pablo, and the Grupo del Norte (North Group) beside and behind the church (which was built over part of the ancient site in 1590).
The Grupo de las Columnas has two main patios, the Patio Norte and Patio Sur. Along the north side of the Patio Norte is the Sala de las Columnas (Hall of the Columns), 38m long with six massive columns. At one end of this hall, a passage leads into El Palacio, which holds some of Mitla's best stonework 'mosaics.' The Patio Sur holds two underground tombs.
The remains of other structures are scattered around the town and for many kilometers around.
If you're coming by public transportation, ask to get off at the fork known as La Cuchilla in Mitla's downtown. From here it’s 1.2km north to the Iglesia de San Pablo and the ticket office for the Grupo de las Columnas.