The basilica consists of 2 parts. The Romanesque lower church dates back to the 12th century and is the oldest building in Bruges. And in the upper one you can climb the spiral staircase from another entrance. This two-level chapel (the name "basilica" was given only in 1923) was owned by the Count of Alsace, who dedicated it to St. Basil the Great, placing his relics there. But after finding the relic of the Holy Blood, the church was renamed. The lower part of the chapel still retains its Romanesque structure.→