on the opposite side is the former franciscan monastery founded in 1567, which was the center of evangelization efforts for the area. it is the oldest such construction in the state of puebla and the church is the only one in latin america which has been in continuous use since its founding. in the courtyard of the monastery, there is a fountain called the fuente de las sirenas (fountain of the mermaids). after years of abandonment, the complex underwent extensive restoration in the 2000s. this work discovered colonial era murals on the interior walls. this mural work contains images of deer, bees and jaguars, houses with thatched roofs and daily scenes with spanish and indigenous people.