Barcelona's Montjuïc Castle, Past & Present

A Very Long History

Barcelona’s iconic castle, located 173 meters above sea level on the mountain of Montjuïc dates back to the 15th century, and has a long and often bloody history. The original medieval fortress was hastily built for defensive purposes in a period of only 30 days following the Reaper’s Revolt in June of 1640. This stone and clay construction was put to the test in the Battle of Montjuïc the following year, during the continuing conflict of the Thirty Year’s War between France and Spain. In later years, the construction would be expanded; in 1694, the walls were strengthened, and the rough fortress was later converted into a castle by an engineer named Pròsper der Verboom, originally of Dutch origin. It wasn’t until the 18th century that it was expanded to the shape we know today.

The strategic fortress was taken and lost multiple times between the years 1705 and 1714, during the War of Spanish Succession, when it was ultimately occupied by the victors—the Bourbons. As the castle had suffered severe damage during the war, the city ordered a series of major renovations between the years of 1751 and 1779; between 1780 and 1799 the castle was expanded even further as the castle’s population grew to over 3,000 people.

French troops took the castle during the Napoleonic Wars in 1808. As the soldiers defending the castle had been ordered not to fight the French army under any circumstances, the structure was taken without any bloodshed.

In 1842, it was used as the main line of defense when the Spanish regent, Joaquín Baldomero Fernández Espartero Álvarez de Toro, bombarded the city of Barcelona in response to a local uprising in protest of his trade policies. It was infamously used as the site of executions, such as of the educator and suspected anarchist Francesc Ferrer i Guàrdia, accused of plotting the assassination of King Alfonso XIII. In 1919, more that 3,000 people were imprisoned in the castle in response to a massive workers’ strike that escalated into violent protest.

The structure was used as a military prison under the Franco regime; for many years, it was a symbol of repression casting an ominous shadow over the city. Between 1936 and 1938 alone, 173 people were executed, including the former President of the Generalitat de Catalunya, Lluís Companys. The space was used as a prison until the year 1960, when the castle partially ceded to the Barcelona City Council (though still under the control of the central government) and transformed into an army base. Three years later, it was opened to the public as a military and armaments museum.

The castle was declared a Cultural Asset of National Interest by the Catalan Government in 1988, and—like many places all around the city—cleaned up and renovated for the Olympic Games in 1992. After lengthy negotiations, the castle was finally returned permanently to the City Council in 2007. In 2008, the city officially declared the site a cultural center, though parts of the fortress were still used militarily through the mid 2010s.

Renovated Structure and Defenses

The castle you see today is much more elaborate than the original structure, largely thanks to military engineer Juan Martín Cermeño. He was charged with strengthening the fortress’ defenses and redesigned the castle completely between 1753 and 1779. Cermeño was one of the most notable military engineers of his era and is also known for completing the construction of the fortress that once stood on the site of Barcelona’s Parc de la Ciutadella—another of Verboom’s projects—which completely reshaped that part of the city. (Making way for the massive military citadel resulted in the demolition of a large section of the historic neighborhood of La Ribera and the creation of the area of the city now known as Barceloneta. The citadel was unpopular with the citizens, and was eventually demolished.)

Under Cermeño, a large chunk of the original castle was demolished, but without touching the main improvements made in the seventeenth century. His new additions included the moat, the covered walkway around the perimeter, and several new structures that adapted to the shape of the hill on which the castle sits. These additions included the entrance bridge and the upward-sloping wall of the façade, which was a major defensive improvement over the previous design of disconnected walls, and four defensive bastions at the corners of its extremities.

A bastion is a defensive structure that projects outwards from the façade of the building. Their construction is designed to prevent would-be assailants from getting close to the main body of the fortress, and to allow the defending troops a vantage point for crossfire. In Montjuïc castle, only the bastion on the seaward side was built from scratch by Cermeño; the rest had already been built under Verboom.

This relatively new bastion featured storage spaces for food and artillery, a drainage system for water that seeped through the embankments, as well as openings in the walls called embrasures that allowed cannons and other artillery to be fired at attackers coming from the sea. These improvements significantly improved the defenses from this side of the castle. When the castle was opened to the public as Franco’s military museum in 1963, the top of this seaward bastion was remodeled so that its embrasures could be used as vantage points for visitors, and its inner rooms were converted into showrooms and a gift shop.

The other three bastions had similar defensive functions, complete with embrasures and storage space for artillery. One of them housed a well connected to an underground cistern that supplied water to the castle. In the 1970s, two of the bastions were converted into a telecommunications complex, due to the castle’s height and privileged position.

The Bridge and the Moats

The lack of a moat was one of the main defensive weaknesses noted by Cermeño when he was given the task of remodeling the building. He subsequently built not one but two moats, and constructed a drawbridge to cross the outer moat, also known as the Santa Eulàlia Moat after Barcelona’s first patron saint.

The bridge’s span leads to the main entrance, which is positioned in the middle of the wall of the main façade. The royal coat of arms of Charles III of Bourbon was formerly mounted on the massive neoclassical gatehouse, but these days is preserved inside the castle so it can be viewed up close and protected from the elements.

After passing through the gatehouse, the entrance tunnel splits to lead to two large spaces on either side that run parallel to the outer wall. According to historical documents, the right-hand side was used by the palace officers and guards, while the left-hand side was a storage space for weapons, artillery and gunpowder. Some records suggest that this space may also have been used as an infirmary and even a prison in times of need. Today, these rooms are used as annexes by the Barcelona City Council.

Inside the gatehouse is the ravelin, the inner covered walkway, the hornwork, the glacis (an artificially-created slope running from the top of the covered walkway to the ground, making the fortress even harder to attack), and demi-bastions: all of these are defensive fortifications built to guard against any assailants who had breached the outer walls. Cermeño made sure that the fortress was built like a proverbial Russian doll, with layer after layer of defenses within defenses. The inner walls are surrounded by the inner moat, or the Santa Elena Moat, which is deeper than the outer moat.

Panoramic Views Above, Dungeons Below

Inside, the covered walkway is a corridor that runs along the perimeter between the two moats. It was turned into a pedestrian promenade when the castle was opened to the public in the 1960s. The roof of the walkway is the highest point in the castle that is open to visitors, and offers 360º views of the city, the sea and the castle itself.

On the roof above the main entrance is a large, rectangular watchtower. While this structure was added during the renovations, the first mention of a watchtower on this site—the highest point in the city—dates back to 1073, where a lookout post was constructed to watch for enemy ships. The tower was transformed over the centuries, and was eventually incorporated into Barcelona’s telegraph network, which sent signals to other military posts around the city starting in the mid 1800s.

The inner area beyond is known as the parade ground, and is a massive, uncovered square or quadrangle located in the highest part of the castle and surrounded on all sides by a pedestrian arcade, which connects to the formerly inhabited rooms of the fortress, including the canteen, bakery, latrine as well as storage spaces. There is a sentry box at each of the four corners of the square.

Although this area functioned as the heart of the fortress, its facilities were not part of Cermeño’s original design. His drawings had originally placed the living quarters behind the inner walls, but for unknown reasons these plans were modified.

When the castle was used as a military prison during and after the Spanish Civil War, these rooms around the parade ground were transformed into prison cells. (The castle didn’t become the city’s main military prison until the Ciutadella fortress—which was used as the city’s main prison until then—was torn down in 1870.) When the space was transformed into a military museum, they were renovated and turned into offices, exhibition halls, and service areas. The moats were landscaped and turned into archery ranges. A large statue of Francisco Franco on a horse was installed in the middle of the parade ground, where it remained until the castle’s acquisition by the City Council in 2007.

The castle’s original dungeons are five cells located below the rooms in the sea-facing side of the parade ground. Historians speculate that these rooms may have existed before Cermeño’s renovations but had possibly been used for another purpose.

Montjuïc Castle Today   

Today, the castle is one of the main attractions in the massive urban park of Montjuïc, which also includes the Miró Museum, MNAC, Poble Espanyol, the Magic Fountain, the CaixaForum, the Olympic Ring, walking trails and much more. It can be reached by cable car, funicular, bus, or by walking, cycling, or driving up from Plaça d'Espanya.

It is now a popular tourist destination thanks to its stunning 360º views of the sea and the city. Its moats are now filled with green grass and multicolored flowerbeds, and even feature a statue that commemorates French scientist Pierre-André Méchain’s contribution to the metric system of measurement, as his discoveries were made from the tower of the castle. It’s difficult to remember the castle’s bloody past, especially when visiting it on a gorgeous sunny day.

The Montjuïc Visitors Center occupies four rooms on the castle grounds, each room with its own historical theme. Montjuïc, a Hill in Barcelona explains the archaeological and historic significance of the mountain itself, and the links between the mountain and the city; Beacon, Fort, and Castle concentrates on the architectural evolution and the significance of the building itself; Montjuïc, Defense and Repression examines both the strategic military importance of the castle, as well as its function as a tool of repression against the city’s population; finally, Prison and Memory focuses on the use of the fortress to imprison, try, and execute political and military prisoners in the nineteenth through the twentieth centuries.

Visitors can also view the hundreds upon hundreds of examples of graffiti carved into the walls of its dungeons by prisoners, which documented everything from their daily routines to their hopes and fears.

The castle is the site of various cultural activities year-round, including seminars, temporary exhibitions, children’s activities and open-air cinema screenings and concert cycles during the summer months. The juxtaposition of fun and educational activities with the still-visible bullet marks on the walls is an example of the interesting and unique, if sometimes strange, environment the city of Barcelona has to offer to its residents and visitors.

Published October 10, 2022, updated May 20, 2025.

Montjuic-Castle-photo-by-Domenico-Convertini-(CC-BY-SA-2.0)-via-Flickr-09.jpg

Montjuic Castle photo by Domenico Convertini (CC BY-SA 2.0) via Flickr.

Castell de Montjuïc

Carretera de Montjuïc 66, 08038 Barcelona

March 1st to October 31st: open daily 10:00-20:00. November 1st to February 28th: open daily 10:00-18:00.

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