It is a small quadrangular plaza formed by the Casa Colorada, the Casa del Venado, a platform that has a stela, and another one that has not been intervened.

This group is associated to the Observatory by means of a small sacbé. This last building was used by the ancient Maya for astronomical observations.

Casa Colorada or Chichanchob: The name of the building is due to the remains of red paint located in its interior, and to the openwork crests. The building must have had a religious and public function, because it has attached to the east a ball game court with reliefs in Maya-Toltec style (Arqueología Mexicana, special edition No. 27, Mexico, Editorial Raíces).

El Caracol or Observatory: So called because of a spiral staircase inside, it has also been named The Observatory, since it is possible that this building, round and erected on two rectangular platforms with different orientation, has served to set astronomical observations. It should be noted that its exterior facade is adorned with masks and human figures surrounded by feathers. Its present appearance is the result of at least six remodeling works. Several constructions were added on the south side, including cisterns, a steam bath and an arch over the sacbe.