On the east side of the main square is the Spanish-colonial style of the Church of Santo Tomás and its monastery built by Dominican friars in 1540 on a pre-Hispanic archeological site. It is customary that the locals enter the church through the main entrance after climbing the 18-step semi-circular stairway that represent each of the months of the Mayan calendar. Visitors enter through the side entrance.

Across the plaza is the smaller El Calvario Chapel used exclusively by the Maya for both Christian and Maya rights.
In accordance with indigenous practices, a Maya Chuch-Cajau priest who clings strongly to his ancestors’ faith arrives with his family. On the lowest step of Santo Tomás Church, black smoke rises from a crude stone altar. The Chuch-Cajau and his family approach the altar. He begins his prayers and burns corncobs. The wife and daughter squat and the boy kneel at his father’s side. Then he begins to turn to each point of the compass and feeds the flaming embers with joc-pom (copal). Now he is sure that the smoke will be carried to the spirits of his ancestors so they will come to plead with his to the divinities. He pleads to Santiago (St. James) so that his prayers will travel enclosed in the smoke. Now the son fills the incense burner with copal embers and the group walks up the narrowing steps to kneel in front of the open entrance to the church.