Sant Climent de Taüll is a form of Romanesque architecture and contains Romanesque artwork. Romanesque architecture is classified by its semi-circular arches on the buildings. It is also best recognized by its massive size, thick walls, round arches, sturdy piers, groin vaults, large towers and decorative arcading. During the time of Romanesque architecture, many more churches were built than castles. The architecture is often a symmetrical plan, and the exterior of the building is very simplistic with clear forms. The building material for the exterior varies in different structures, although brick is generally used. The arches, doors, windows, vaults and arcades used during this time are almost always semicircular.