The biggest attraction of Mitla is the unique decoration of its buildings based on freckles, an element that is not repeated in any other archaeological area of the country.

The area consists of five construction groups known as: Grupo del Norte (North Group), Grupo de las Columnas (Column Group), Grupo del Arroyo (Creek Group), Grupo del Adobe or del Calvario (Calvary Group) and Grupo del Sur (South Group). These last two come from an earlier time and have a clear similarity with the style of Monte Albán, with plazas delimited by palaces erected on platforms.

The Column Group is characterized by the use of monolithic columns. The great Hall of the Columns is rectangular. Entering the hall there is a narrow door to enter the main palace. The doorframes are decorated with mosaics of intricately worked small stones perfectly fitted into stepped fret (geometric) patterns. When leaving the passage, there is the Patio of the Frets, from where there is access to each of the four rooms, decorated by three boards with mosaics of carved stone with different geometric patterns in each side; The freckles are made up of thousands of tablets of polished stone, crimped together without any mixture.

In several buildings you can see traces of paint, especially red.

In the 17th century, the temple of San Pablo was built over the rooms of Patio C, with materials from ancient pre-Hispanic palaces.