Fort National is a fort on a tidal island a few hundred metres off the walled city of Saint-Malo. The great military architect Vauban had it built in to protect Saint-Malo's port. The fort was originally called Fort Royal. This was originally the site of a beacon that was lit at night to act as a lighthouse. Latter a gallows occupied the site. A model in Saint-Malo's history museum suggests that a battery may have occupied the site before the erection of the Vauban fort. Construction seems to have taken from to The fort augmented the defences of the city, and was part of a chain of fortifications that stretched from Fort-la-Latte to Pointe de la Varde.
The original fort was a rectangle, built of granite, with two half bastions at the south, protecting the gate. A drawbridge gave access across a dry moat. Inside the fort there is a long building that contained quarters for the officer and troops, and equipment rooms. For their attack on Saint Malo the English had brought a vessel packed with gunpowder to use as a floating mine against the city's defences, but it ran aground short of its target.
The crew of the vessel were able to set off their bomb, but it was too far from its target to do any harm. At the time, the fort was armed with 14 guns on marine carriages and three mortars.
Other accounts suggest that the fort originally had 23 guns, with the mortars being added in The fort contains an underground cistern with a capacity of 50, liters, fed by gutters, and accessible both by a trapdoor and a well. The garrison held its ammunition in an underground bomb-proof magazine with a vaulted ceiling. Angled apertures provided light and air. In the government added a wall pierced for small arms that encircled about three-quarters of the fort.
The wall was intended to protect the fort against infantry attack from the land or by troops landed on the rocks on which the fort stands. The engineers also added a small bastion in front of the gate. This gave the fort a total area of about square metres. In the fort received recognition as an historic building. However, in the government sold the fort to a private buyer.
