Castel Sant'Elmo is a medieval fortress located on a hilltop near the Certosa di San Martino, overlooking Naples. Documents date a structure at the site from 1275, from the era of Charles d'Anjou. Known originally as Belforte, it was likely a fortified residence, surrounded by walls, its entrance gate marked by two turrets. In 1329, using designs by the Sienese architect Tino da Camaino, king Robert of Naples enlarged the fortress.
The Angevin fortress was severely damaged in an earthquake in 1456, which demolished the external walls and the towers. The Aragonese rulers of Naples, and notably Don Pedro de Toledo, the first governor and cousin of the Viceroy, included it in a comprehensive scheme designed to fortify the land perimeter of the city, based on four separate strongholds. Castel Sant'Erasmo acquired its hexagonal star shape between 1537 and 1547 under the designs of Pedro Luis Escrivafrom Valencia, a military architect. The daring hexagonal shape drew fierce criticism from his contemporaries, to such an extent that in 1538 Escriva defended his design in a published Apologia.
The castle served as an autonomous military outpost, with a governor who had absolute authority over both military and civilian matters. Around the parade grounds were situated the officers' quarters, chaplain's house, a church (1547) designed by the Spanish architect Pietro Prato, and the surviving buildings from the Angevin Belforte. Don Pedro de Toledo's funerary monument (1588) is found in the sacristy of the church.
In 1587 the munitions depot of the castle was struck by lightning, and exploded, destroying the church, the chaplain's house and the officers' quarters. Reconstruction was carried out between 1599 and 1601 under the architect Domenico Fontana. Despite successive rebuildings over the centuries, the castle conserves its original structure. Built of volcanic tufa, it overlords over Naples, and ever since the famous Tavola Strozzi incident (late 15th century), for centuries it was a symbol and bastion of government oppression. In 1604 it was used to imprison Tommaso Campanella, branded as a heretic, and in 1799 the patriots of the Neapolitan Revolution, including Gennaro Serra, Mario Pagano and Luigia Sanfelice. With the departure of the Bourbon garrison in 1860, it remained a military prison until 1952, when the prison was transferred to Gaeta.
Today there are several permanent art exhibits in the castle. One of the most unique is the railing featuring an inscription in braille which was installed in 2015. The railing, which is more than 30 feet long and dotted with braille letters, is above the drill grounds on the northernmost wall of the castle near the west corner.
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.