In order to provide maximum protection for the new Arsenal built at Rochefort in 1666, Louis XIV demanded an intensification in the fortification projects along the coast of Aunis and Saintonge, and his orders were duly carried out.
With the aim of cutting off access to Rochefort harbour from the south by enabling the defensive cannons to cross fire, the idea came about to build a fort on the outcrop beyond Le Chapus, which is around 2 mi from the Château d'Oléron citadel.
On 16th December 1690, a letter from the Marquis de Louvois, minister of war at the time, addressed to Michel Bégon, head of the French Navy at Rochefort, confirmed the project had been ratified by Louis XIV.
The rock at Le Chapus, which only emerges from the sea at low tide, became the base for an oval fort designed by François Ferry, the engineer responsible for Atlantic fortifications. Work started on the foundations at the beginning of 1691, and was to continue until 20th October the same year.
These foundations, which on their own used up half of the total planned budget of the project, were designed to support a fort with two tiers of cannons and two turrets. This building was to cover the whole rock and would be connected to the mainland by a 400m road that would sink under the sea at high tide.
However, when Vauban took over the project on the death of the Marquis de Louvois, as general commissioner of the country's fortifications he considered the project far too expensive and abandoned it (Vauban was mostly annoyed for having been overlooked during the design phase).
Making the most of his favour with the king, Vauban modified the previous plan, reducing the design from an oval to a horseshoe shape, and the shell of the fort was completed in 1694.
Fort Louvois was the last maritime bastion built by Louis XIV and was honoured with a medal that can still be seen on its façade, framed by the statement: "1694 - Arx chaputiana securitas littorum", which can be translated as: "With this fort at Chapus, the security of the coastline is complete".
Fort Louvois was maintained until the First World War by the state before being abandoned for 10 years, and in 1929 it was named a Historical Monument.
It was significantly damaged by Second World War bombing, and remained in this dilapidated state for a number of years before being sold by the government.
On 28th April 1960, it was purchased by the town of Bourcefranc, which intended to open a maritime museum on the site. In the 1960's the Académie des Beaux-Arts saw to its restoration and in 1972 it opened once more, only this time to the public.
Having started as a military fortification, the Fort de Louvois has, in modern times, become a cultural space.
Its keep currently houses the oyster museum, where visitors can learn about all the different aspects of oyster farming in the Pays Marennes-Oléron area, with excellent 3D educational models indicating where the oyster beds of the region are to be found.
The ground floor of the keep is given over the history of the fort, which is traced back by means of a permanent exhibition. The barracks house models of the fortifications up and down the coast of Charente.
Contact: Tourist Information Office
65 bis, avenue Jean Jaurès, 17560 Bourcefranc-Le-Chapus, France
Tel.: +33 (0) 5 46 85 07 00
In July and August: daily from 10:30am to 6:30pm
Self-guided visit or guided tour - free boat shuttle at high tide (closed on 14th July for fireworks display)
During French school holidays, and in June and September: open at low tide
All year round: guided tour on prior appointment for a minimum of 10 people at low tide
Adult price: £4.80
Child price (4 to 12 years): £1.90