This is one of the most remarkable bunker sites built by German forces during their occupation of France during the Second World War.
Consisting of two massive, special construction buildings – this defensive position can be found at the end of Boulogne-sur-Mer’s 3km-long Digue Carnot breakwater.
Construction began on the breakwater in 1880 and would continue in stages over the next 80 years, creating a structure designed to protect the port and city from the sea, safeguarding one of the busiest ports in northern France.
However, the additional concrete constructions made to it, and the weapons added, during the German occupation from 1940 onwards were to initially designed to protect the area from attacks coming from the air. It would later boast anti-ship guns too.
During the Second World War, Boulogne was classed as a ‘Festung’, of fortress city and was surrounded by more than 50 bunker sites, including defensive gun casemates, radar stations, communications, and HQ centres.
The port itself was initially used as a staging area for Operation Seelow, the planned invasion of Britain, which never came to fruition, and there are images from 1940 showing hundreds of landing barges lined up to carry German troops to the beaches of southern England.
Later on, the port would be a safe haven and supply location for Kriegsmarine ships, and there was even an S-Boat facility built, along with a massive torpedo and mine storage bunker.
The S-Boat base was almost completely destroyed by Allied bombing, along with much of the port area, and the torpedo bunker is the largest of just a few scattered remnants which can be seen today.
Outside of the port, there are many bunkers to be found, with the constructions at the end of the breakwater the most westerly of them all.
Extending nearly two kilometres out to sea from the port entrance, the breakwater was to be a prime location for a first response site built to intercept incoming air attacks.
To the Germans, the complex was known as Stutzpunkt 299 Stechpalme – which translates to Holly in English and is one of many sites named after plants and flowers in this area.
The site features two special construction buildings at the tip of the breakwater.
Connected by concrete, both are 40m long by 16m wide, and feature three levels of solid concrete constructions for defensive weapons.
The first weapons to be installed here came in 1943 when Luftwaffe anti-aircraft guns were positioned on the upper levels.
Two were the infamous 88mm Flak 18 guns – one on each of the buildings – plus two 40mm Bofors cannons, known to the Germans as 4cm Flak 28.
There were also a 2cm Flak 38 Vierling gun – the four-barrelled version – and a 60cm searchlight, both positioned on the building at the outer end of the breakwater.
By 1944, the larger of the guns – the 88mm and 4cm – were removed from the structures as the Luftwaffe Flak Battalion handed the site over the Kriegsmarine.
Further construction took place in 1944 with the addition of a concrete casemate built on the upper level of the inner building.
This would house a 7.5cm FK231(f) gun, an artillery weapon of French origin – built by Schneider and known as the 75mm Model 1897 - captured during the occupation of France.
A second one of these guns was positioned on the outer building, in the place where an 88mm AA gun once stood, and a second 2cm Flak 38 Vierling gun was also added to the site.
The lighthouse at the end of the breakwater is a post-war addition and was the first automated lighthouse in France in 1968. It stands where the 2cm Flak 38 Vierling gun was once located.
Due to the lighthouse’s construction, this building no longer accessible to the public.
It’s believed the outer building once featured as many as 14 rooms on its lower level, and around eight on the intermediate level.
The inner building can easily be explored and from the main entrance off the breakwater you step into the first large room of the lower level.
There are six additional rooms on this level plus a central staircase to the upper floors.
The lower level rooms would have been used as barracks, a kitchen and mess, a workshop, and for storage.
On the intermediate level, it’s likely the two large rooms here would have been used to store ammunition for the guns on the top level, accessible by a second set of concrete stairs.
The breakwater is open to the public but it’s advisable to only visit on good weather days and don’t stray too close to the edges in windy conditions as there aren’t any barriers along the length to prevent a long drop off the side.
The breakwater is a regular location for sea anglers, and you’ll need to be careful when walking behind them. Park near the wind turbines at the base of the breakwater but be aware a lot of construction traffic uses this area too.