Menorca, the easternmost of the Balearic Islands, is an island shaped by the sea and a fascinatingly diverse history. Its strategic location made it a coveted enclave since antiquity, sought after by the Phoenicians, Romans, Muslims, Aragonese and, later, the French and British. This rich history, combined with its natural beauty and authentic character, has resulted in a landscape dotted with numerous fortresses well worth visiting. Discover the castles in Menorca that you simply cannot miss.
San Felipe Castle
Located on the southern shore of the entrance to Mahón harbour, San Felipe Castle was one of the first bastioned fortifications built in Spain. Its origins date back to 1552, when the Spanish Crown decided to reinforce the island's defences against attacks by the Turkish fleet in the Mediterranean.
The Italian engineer Juan Bautista Calvi redesigned the original project and erected an imposing fortress adapted to modern artillery. The English reinforced it, the French conquered it in 1756, and, after successive changes of sovereignty, it was partially demolished by order of Charles IV in 1805.
Today, its underground galleries – restored and turned into a museum – can be visited, giving a sense of the sheer scale of this fortress in Mahón, a key site in Mediterranean military history.
Santa Águeda Castle
High on a hill between Ferreries and the north coast stand the ruins of Santa Águeda Castle. Built by the Muslims on an ancient Roman castrum before 1232, it was one of the main defensive strongholds of Islamic Menorca under the Caliphate of Córdoba.
In 1287, it became the last bastion of Muslim resistance against the conquest of Alfonso III of Aragon, and was later destroyed by order of Peter IV. Now a listed Site of Cultural Interest, the remains of walls, cisterns and defensive structures can still be seen.
The climb to the castle – along an ancient Roman road – rewards visitors with spectacular panoramic views of the island's interior and north coast.
La Mola Fortress
Dominating the entrance to Mahón harbour stands the impressive La Mola Fortress, also known as the Castle of Isabel II. Commissioned in the mid-19th century by order of the queen at a time when foreign invasion was feared, this fortification boasts thick walls, moats, batteries, galleries and cannon emplacements.
Although it never saw actual combat, its size and complexity make it one of the most important fortresses in Spain. Today it is open to the public, with tours of its tunnels, courtyards and bastions.
San Antonio Castle
San Antonio Castle, in the port of Fornells, was built in the 17th century during the reign of Philip IV to protect this strategic bay in the north of the island. Its presence was crucial to the development of the town of Fornells, which grew up around the fortification.
Following British rule, the castle was dismantled by the Spanish, as happened with other Menorcan defences. Today, only traces of its original structure remain, though its layout and ruins give a glimpse of its former design. Nearby stands the Fornells Tower, which completes the defensive system.
San Nicolás Castle
In Ciutadella, next to the port entrance, stands the Castle of San Nicolás, a defensive tower built in the late 17th century to protect the city from maritime attacks. With an octagonal floor plan and austere lines, it is a fine example of the coastal towers erected in Menorca to watch for pirate raids.
Although smaller than other fortifications on the island, its location makes it a highly photogenic and easily accessible spot. The surrounding area offers magnificent views over the port of Ciutadella, especially at sunset.
Fort Marlborough
Located in Cala Sant Esteve, near the entrance to Mahón harbour, Fort Marlborough is one of Menorca's most unique military constructions. Built by the British in the 18th century during their rule of the island, it is named after General John Churchill, Duke of Marlborough.
Unlike other, more visible castles, much of the fort is carved into the rock, with underground galleries, passageways and chambers. Its purpose was to reinforce the defence of the strategic port of Mahón alongside San Felipe Castle.
Today, Fort Marlborough has been restored and is open to the public, allowing visitors to explore its tunnels, discover how soldiers lived and understand the importance of Menorca in European naval disputes.
