It replaced another smaller church that burned down in the fire of 1503, and it is the second largest church in Gipuzkoa, covering 1,630 square metres.
It took more than 200 years to build it. It combines various different styles: Basque Renaissance, baroque, neo-classical...
From all the architects, master stonemasons and artisans that worked on its construction, we have to highlight Martín Carrera. He built the baroque style facade, with the belltower in the middle and two small towers at the sides.
Inside it maintains the Romanesque facade of the hermitage of St. Stephen, brought from its place of origin, and also the sculpture of St. John the Baptist, the patron saint of Tolosa.