As Fort Boyard was built
A bit of history: in 1666, Colbert, finance minister of France under Louis XIV, ordered established shipyards to build ships near the town of Rochefort, which is located at the mouth of the Charente River.
Fort, built in the middle of the strait, along with shore batteries could block the passage to the shipyards before making the enemy ships "fire barrier".
However, the legendary engineer fortifier Sebastien Le Prêtre de Vauban, Louis XIV, who offered to lead the building, refused, objected to the king: "Sire, it is easier to grasp the moon teeth than to build a fortress in this place."
The idea of the fort built back in the early XIX century. By the time construction technology has allowed the construction of such a fortress, and the need to remain very urgent in it - the foreign policy of Napoleon I of France greatly complicated relations with Britain.
Construction of the fort began in 1801 on the already existing in the Strait of sandbar on which the title and was the name of the fort.
In the construction of the fort foundation stone blocks are mounted directly on the seabed. Soon builders are faced with serious technical difficulties - stone blocks left in the ground under its own weight, warp and went home.
As a result, in 1809 the construction of the fortress had been suspended and resumed only in 1837, during the reign of Louis-Philippe I, when relations with Britain once again became very strained.
The construction of the fort was the "protracted" - the castle was completed only in 1857. The final construction was very impressive - the fort had a length of 68 meters and width of 31 meters, and the height of the walls reaches up to 20 meters.
Bayar garrison consisted of 250 people. However, by the time of completion of the construction of the fort it was found that in general, the fortress is no longer needed. For more than 50 years that have passed since the moment of laying the fort, long range artillery greatly increased, and now the coastal batteries easily blocked Strait.
Thus, the need in a new fort has disappeared, but it remained the responsibility of the Military Department of France and was later used as a prison, is not participating in the hostilities.