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Fort de Bertheaume today

France · Restored

Fort de Bertheaume

Fort de Bertheaume is a coastal fortification on a tidal islet off Plougonvelin in Brittany, France, long used to control the Goulet de Brest. The site preserves multi-period masonry batteries and a connecting footbridge, and has been rehabilitated for public visits after military abandonment.

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Photograph via Wikimedia Commons

Its prime

1890

Today

Restored

As it stood in 1890

What Fort de Bertheaume looked like in its prime.

A compact granite tidal islet topped by a low, angular stone fort with thick grey curtain walls that trace the rocky summit; terraced artillery batteries step down the seaward side in multiple levels linked by stone stairs, including a semi-circular battery and a bastion near the top. Masonry embrasures and posterns open toward the sea, an arched pier supports the narrow landward footbridge, and the exposed rock shoreline and clear Atlantic water define the setting.

Its story

The story of Fort de Bertheaume.

Fort de Bertheaume occupies a tidal island off Plougonvelin in Finistère, its steep cliffs making it easily defended for centuries; today a footbridge links it to the mainland. Title to the site passed from the Viscount of Léon to the Duke of Brittany, and in January 1366 John V, Duke of Brittany, transferred custody of Brest and its defences to Edward III of England, not retrieving Brest until 1397.

In 1677 the engineer Sainte Colombe proposed to Louis XIV 'to install cannons on the small island of Bertheaume near the port of Trehire on the ruins of the castle of the former Dukes of Brittany', and from the 17th century the fort's role was to monitor the Goulet de Brest, the straits of Brest. Abandoned by the military, its multi-period masonry batteries have since been rehabilitated for public visits.

Step inside

9 places to explore in 1890.

The record describes 9 distinct spots at Fort de Bertheaume, including 1 interior: barracks and powder magazine. Create your own photoreal reconstruction and explore every one, more scenes means more rooms, more angles, and more of the place to stand in.

Mainland footbridge approachGateway and archway at island landingUpper bastion and parapetSemi-circular batteryTiered eastern batteries (four levels)Stone stair ramps between batteriesBarracks and powder magazineMainland casemates and battery (late 19th century)Postern and cliff-foot access

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Nearby

Landmarks within reach of Fort de Bertheaume.

La Jument, FranceLighthouseLa Jument34 km away

Questions about Fort de Bertheaume

What is the history of Fort de Bertheaume?

Fort de Bertheaume is a medieval stronghold that became a coastal artillery fort in the 17th century. Title passed from the Viscount of Léon to the Duke of Brittany, and custody of Brest and its defences was transferred to Edward III of England in 1366. The castle was destroyed in 1558, then rebuilt and strengthened under Vauban from 1689 onwards.

What is inside Fort de Bertheaume?

Fort de Bertheaume contains barracks and powder magazines, including one magazine 13 metres underground. The fort also has a bastion, a semi-circular battery, tiered batteries connected by stairs and posterns leading to the foot of the walls. The lower battery has been converted into an exhibition space and open-air theatre.

Why was Fort de Bertheaume built, and what was it used for?

Fort de Bertheaume was built and expanded to control the Goulet de Brest, the straits leading towards Brest harbour. From the 17th century it monitored vessels and helped defend the port against attack or landing. Its military purpose ended after the French military abandoned the fort in the late 19th century, although it was later occupied during the Second World War.

Was Fort de Bertheaume ever attacked or besieged?

Fort de Bertheaume was attacked and captured in 1558, when an Anglo-Dutch force destroyed the castle during a coastal expedition. Its battery later fired on British forces during the attack on Camaret-sur-Mer in 1694. During the Second World War, German troops occupied the site, and its garrison surrendered on 8 September 1944 after resisting the Liberation.

What did Fort de Bertheaume look like in its prime?

Fort de Bertheaume is a compact granite fort on a tidal islet, with low angular stone walls following the rocky summit. Terraced artillery batteries descend the seaward side in several levels, including a semi-circular battery and an upper bastion. Embrasures and posterns face the sea, while an arched pier supports the narrow footbridge to the mainland.

Is Fort de Bertheaume still standing or is it a ruin?

Fort de Bertheaume is still standing and has been restored rather than left as an unmanaged ruin. Its multi-period masonry batteries survive, together with the connecting footbridge and mainland defences. The site was rehabilitated after military abandonment, and archaeological examination accompanied the work to make the fort visitable.

Can you visit Fort de Bertheaume?

Fort de Bertheaume can be visited by the public. A footbridge now connects the tidal island to the mainland, and the fort and surrounding area underwent rehabilitation to make the site visitable. The mainland part accommodates an open-air theatre, while the lower battery contains an exhibition space and an open-air theatre.

Where is Fort de Bertheaume?

Fort de Bertheaume is on a tidal islet off Plougonvelin, in Finistère, Brittany. The islet is now connected to the mainland by a footbridge and was historically positioned to monitor the Goulet de Brest, the straits leading towards Brest. It is located within the administrative territory of Plougonvelin.

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