The collegiate church is one of the oldest buildings in the city and was named after its original location outside the city walls, in the highest point of the capital. For centuries it was the church of reference for merchants, craftsmen's guilds, and tradesmen.
Of the first Romanesque church, built around 1150, only the main chapel remains. Between the 13th and 16th centuries the building was expanded and in 1889, the architect Juan de Ciórraga went on to make significant renovations, the most important being the replacement of the medieval façade with the contemporary neo-Romanesque style façade.
The building, elevated to the status of collegiate church in 1441, is surprising for its structural irregularities, such as the misalignment of the apse on its axis, the slope of the floor and the overhang of the arches of the side naves.
There are three very interesting porticoes. The western one, in Gothic style, depicts an Epiphany with the Virgin Mary, the Christ Child, the Three Wise Men and Saint Joseph. On the north portico is the martyrdom of Saint Catherine and on the south door, an unidentified scene appers, which could correspond to the Apostle St. James accompanied by pilgrims.
Inside, there is an interesting display of late medieval tombs of illustrious figures from the city, such as the first abbot of the collegiate church, located in the main chapel.
