Santiago Cathedral of Bilbao was originally built during the 14th-15th centuries as Bilbao's main parish church, and was only declared cathedral in 1950 when the Roman Catholic Diocese of Bilbao was officially created. Its origins probably date to well before the foundation of the city in 1300, when Bilbao was little more than a small enclave of fishermen.
The church is consecrated in honor of the apostle Saint James the Great (Santiago), by virtue of being a point of transit for the pilgrims that followed the Northern branch of the Way of Saint James.
Architecturally, the present building is a mixture of styles: from the 15th century Gothic of the cloister and the main vault, where of special interest are the cloister and the beautiful portal that gives access Correo street (Puerta del Angel), to the ostentatious Gothic Revival façade and spire.
A curious custom is the addition of stone carvings of local merchants along the buttresses of the main vault.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.