Blockhaus du fort d'Aleth, German military fortification in Saint-Malo, France.

The Blockhaus du fort d'Aleth is a concrete fortification with reinforced walls that remains as part of the defensive structures on the Aleth peninsula. Its heavy construction and thick walls clearly show the military engineering needed to protect the coastline during that period.

German forces constructed this defensive structure in 1943 to control maritime traffic and secure their positions along the French Atlantic coast. Its construction occurred during a period when coastal defenses were being reinforced to resist potential Allied landings.

The blockhouse is listed as Stützpunkt Ra 230 in German wartime records, and its name survives in local memory alongside the fort d'Alet toponym. Visitors can still read the concrete massing and embrasures that show how the position was manned. The site is now studied by heritage groups documenting Atlantikwall remains on the Emerald Coast.

The blockhouse sits on the Aleth peninsula and is best reached on foot from Saint-Malo's historic center. Access depends on tides and weather conditions, so it is wise to check local conditions before planning your visit.

French heritage authorities identified this structure as endangered in 2021 and ordered special preservation measures to protect it. This makes it a rare example of a German wartime structure that now receives formal protection under French heritage law.