The Royal Basilica of Our Lady of Atocha is one of the six basilica churches in Madrid. The buildings on the site have a long history. The original name refers to a lost icon from a chapel which was found during the time of the Reconquista. The old church was in disrepair and rebuilt in the 1890s in a Neo-Byzantine style designed by Fernando Arbós y Tremanti.
The church was destroyed during the Spanish Civil War and reconstruction completed in 1951.
Adjacent to the church is the Pantheon of Illustrious Men or Panteón de Hombres Ilustres of Madrid. It holds the remains of only a former president of the council of ministers, José Canalejas, however it also contains a number of interesting monuments from and just after the turn of the 19th century.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.