Castel Sant'Elmo is a medieval fortress located on
Vomero Hill adjacent to the
Certosa di San Martino, overlooking
Naples
Naples ( ; ; ) is the Regions of Italy, regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 908,082 within the city's administrative limits as of 2025, while its Metropolitan City of N ...
, Italy. The name "Sant'Elmo" derives from a former 10th-century church dedicated to Sant'Erasmo, shortened to "Ermo" and, finally altered to "Elmo". Located near the upper terminus of the
Petraio, one of the city's earliest pedestrian connections between upper and lower Naples, the fortress now serves as a museum, exhibition hall, and offices.
History
Documents date a structure at the site from 1275, from the era of
Charles of Anjou
Charles I (early 1226/12277 January 1285), commonly called Charles of Anjou or Charles d'Anjou, was King of Sicily from 1266 to 1285. He was a member of the royal Capetian dynasty and the founder of the House of Anjou-Sicily. Between 1246 a ...
. 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
300px, Tomb of Antonio d'Orso, in Florence.html" ;"title="Santa Maria del Fiore, Florence">Santa Maria del Fiore, Florence.
Tino di Camaino (c. 1280 – c. 1337) was an Italian sculptor.
Biography
Born in Siena, the son of architect Camain ...
, king
Robert of Naples
Robert of Anjou (), known as Robert the Wise (; 1276 – 20 January 1343), was King of Naples, titular King of Jerusalem and Count of Provence and Forcalquier from 1309 to 1343, the central figure of Italian politics of his time. He was the thir ...
enlarged the fortress described in documents as ''palatium in summitatae montanae Sancti Erasmi''. Camaino also supervised construction of the adjacent Carthusian monastery of
San Martino. By 1336, the palace was referred to as a ''castrum'' or castle, and work continued under Camaino till his death in 1343.
Attanasio Primario and
Francesco di Vico then directed construction. By 1348 documents refer to the building as ''castrum Sancti Erasmi'', probably because a chapel dedicated to Saint Erasmus was originally located on the site. 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 Escriva from
Valencia
Valencia ( , ), formally València (), is the capital of the Province of Valencia, province and Autonomous communities of Spain, autonomous community of Valencian Community, the same name in Spain. It is located on the banks of the Turia (r ...
, 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''.

In fact, with its double
tenaille, numerous embrasures in the bastions and high walls surrounded by a moat, the castle was admirably suited to the topography of the site and the strategic and defensive functions. In 1538 a commemorative inscription was placed above the entrance gate, surmounted by
Charles V Charles V may refer to:
Kings and Emperors
* Charles V, Holy Roman Emperor (1500–1558)
* Charles V of Naples (1661–1700), better known as Charles II of Spain
* Charles V of France (1338–1380), called the Wise
Others
* Charles V, Duke ...
's coat of arms and the two-headed
Imperial eagle.

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
Tommaso Campanella (; 5 September 1568 – 21 May 1639), baptized Giovanni Domenico Campanella, was an Italian Dominican friar, philosopher, theologian, astrologer, and poet.
Campanella was prosecuted by the Roman Inquisition for he ...
, branded as a
heretic
Heresy is any belief or theory that is strongly at variance with established beliefs or customs, particularly the accepted beliefs or religious law of a religious organization. A heretic is a proponent of heresy.
Heresy in Christianity, Judai ...
, 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
Gaeta (; ; Southern Latian dialect, Southern Laziale: ''Gaieta'') is a seaside resort in the province of Latina in Lazio, Italy. Set on a promontory stretching towards the Gulf of Gaeta, it is from Rome and from Naples.
The city has played ...
.
Present
It continued to be military property until 1976, when a large restoration project was undertaken by the provincial authority of the ''Provveditorato alle Opere Pubbliche'' of Campania. In seven years the original castle was freed of centuries of accretions, and made structurally sound, recreating the original galleries, parapet walkways and underground chambers, where an auditorium seating 700 has been created. In 1982 the site was handed over to the ''Soprintendenza per i Beni Artistici e Storici'' of Naples, and the Bruno Molajoli Art History Library was installed in an upper story of the old prison block.
The former Marine headquarters now houses the castle administration and some administrative offices for Naples, including the Catalogue Office, Photographic Archives and the Thefts Office.
There are now several permanent art exhibits in the castle, including a railing more than 30 feet long carrying a
braille
Braille ( , ) is a Tactile alphabet, tactile writing system used by blindness, blind or visually impaired people. It can be read either on embossed paper or by using refreshable braille displays that connect to computers and smartphone device ...
inscription, installed in 2015 above the drill grounds on the northernmost wall of the castle near the west corner. Two other installations include a large metal helmet near the railing and a conical metal sculpture, approximately 15 feet in diameter at the bottom, with cutouts in the drill grounds.
Sources
*
''A handbook for travellers in southern Italy''by John Murray (Firm), page 99–100. 1883.
External links
*
{{DEFAULTSORT:Sant'elmo
Buildings and structures completed in the 14th century
Castles in Naples
National museums of Italy