The patron of Cumiana is the Nativity of the Blessed Virgin Mary, celebrated on 8 September. The main settlement of the municipality, made up of some sixty hamlets and localities, is in the Motta district, where the main parish church also stands, dedicated precisely to the Nativity of Mary. The present church, in Baroque style, with a nave topped by an elliptical dome, owes its structure to the Morari architects: Giovan Battista, who designed it but died before it was built, and his son Felice Nicolao, who completed it in the mid-18th century; it is Piedmont's largest oval-plan church after the sanctuary of Vicoforte.
Directly opposite, still on the Motta hill, stands the church of the confraternity of the same name, where for eighteen years, between the Immaculate Conception and Epiphany, an animated nativity scene covering 60 square metres has been set up, renewed each year.
