Capilla del Sagrario de la Iglesia de Nuestra Señora de la Asunción

Built in the 16th century. The interior was given this appearance in 1743-1747, under the direction of architect Jerónimo Sánchez de Rueda. Notice the clear light of the Age of Reason, just as in St. Paul's in London. No more dim purple gothic light.

As you can see, the outside hardly hints at the riches within.

Not normally my favorite style, but this is amazing.