Old Monastery of Sant Pau del Camp, Barcelona

Beautiful structure of a former Benedictine Monastery. Sant Pau del Camp is Barcelona's oldest preserved church probably built around the 9th century. A description by catalunya.com states "it has a structure in the form of a cross, with three apses and an octagonal tower in the transept. The interior is covered by simple barrel vaults and a dome in the transept. It has a Greek cross layout and the south arm of the transept has a door with a pointed arch. There is a group of three semicircular apses. The façade is ornamented with Lombard arches and is topped with remains of fortifications."

Beautiful old church and cloisters. The dome is especially interesting. There were no other visitors when I was there (a weekday in early November), quite a contrast to other sites in the city.