The structure called the Oval Palace occupies the southern side of the square; its dimensions are 26 meters by 23.50 meters, with a height of 11.50 meters. The building's construction clearly shows three stages. The oldest, which gave the palace its name, consists of several stacked oval-shaped levels with sloping walls and a structure on top that likely supported a now-lost wooden level.

The next stage consists of 10 rooms surrounding the earlier structure on three sides: north, east, and west; eight are at the square level, and two more were built on the second level of the main facade, that is, on the north side. This building had a mixed function, as the rooms served as residences for the high aristocracy or priests who lived in one of the main buildings of the inner city; at the same time, the miniature sanctuary clearly shows its use for ritual purposes, as in other similar structures. In front of the building are four monolithic braziers, two of which have anthropomorphic faces.

Finally, in the third stage of construction, a small temple was added to the Oval Palace, crowning the complex. Various offerings and burials were found in this building, among which stands out the burial of an infant placed inside a pot covered with a plate, and inside, as an offering, were two ear plugs and several jade beads, undoubtedly belonging to one of the deceased’s parents.