The parish church is a building in honour of Saint Thomas the Apostle and was declared an Asset of Cultural Interest on 4 June 1931.
It is located at the foot of the hill of La Mota, the primitive nucleus of the town, currently known as “La Atalaya”, and was built on top of an earlier building made of ashlar stone.
The German “hallen kirche” or hall plan is divided into three naves of equal height without transept with fifteen star-shaped ribbed vaults and different geometric arches over pointed arches and attached columns and pilasters.
Inside, the choir and the altarpiece stand out. In the choir we can contemplate the seating from the end of the 17th century and the organ from 1798 by Domingo Garagalza and the great altarpiece of the main altar is the largest in the whole of La Rioja, dating from 1730 and was made of polychrome wood with great decoration that gives us the sensation of filling the whole space, the “Horror Vacui”.
On the outside, it is worth highlighting the main doorway under an arch with scenes of Calvary and imagery of the Apostles and the Eternal Father together with the coats of arms of the Velasco family. It is a Plateresque style work by Felipe Vigarny, one of the most outstanding sculptors of the Spanish Renaissance. The decoration with candelieri, grotesques and garlands made of stone and restored in 1999, introduces a new Italian Renaissance style of sculpture in La Rioja and represents the transition from the old church to the current church structurally in the manner of a triumphal arch.
But undoubtedly the most special part of this great construction is the tower, which set a precedent for many others that followed, such as the tower of Santa María la Redonda in Logroño (1742) or that of the Cathedral of Santo Domingo de la Calzada (1765). Its lower part is the work of Juan de Ramón from 1671 in Gothic style and square in shape. The upper part, more baroque, is by Agustín Ruiz de Azcárraga from 1720 and has an octagonal bell body crowned by a dome with a lantern.