Forteresse de Mimoyecques

About the museum

The Mimoyecques fortress is a wholly underground structure dug into the chalk of the northern Boulonnais. It was meant to house the “super cannon V3”, a multi-chamber weapon intended to bombard London. Its code names were “Wiese” and “Bauwerk 711”. From 1943 to the summer of 1944, more than a thousand men, largely forced laborers of many origins, dug a network of galleries serving five firing shafts with five guns each, which were supposed to launch 1,500 shells a day.

On July 6, 1944, Tallboy bombs dropped by the 617 Squadron of the Royal Air Force hit the heart of the structure, ending the threat. The Germans abandoned the site a few weeks later, and in May 1945 the British blew up the fortress so that it could no longer serve as a military base.

Opened as a museum in 1984 by private owners, the fortress was bought in 2008 by the Conservatoire d’espaces naturels and reopened to the public in 2010. From mid-April to mid-October, the Communauté de communes de la Terre des 2 Caps handles visitor reception. For the rest of the year the site is closed so that the bats can hibernate: the galleries are one of the main hibernation sites for bats north of Paris, which is why the site was classified as a regional nature reserve.

Highlights

• Underground galleries of the V3 cannon base
• World War II memorial site in the chalk of the Boulonnais
• Regional nature reserve and bat hibernation site
• One-hour guided tours
• Educational booklet for children

Permanent exhibition

• Galeries de la forteresse – Visit of the underground galleries of the V3 cannon base and of the chalk quarry face.

Founded

1984

Operated by

Communauté de communes de la Terre des 2 Caps

Admission & discounts

Prices published by the site for the 2025 season. Free entry with the Pass éducation. Payment by bank card, cheque, cash or ANCV tickets.

Accessibility

• Wheelchair accessible
• Elevator: no information
• Accessible restroom: no information
• Accessible parking: no information
• Service dogs welcome
• Tactile models & exhibits: no information
• Sign language tours: no information
• Easy-to-read materials: no information
• Audio description: no information

The fortress is described as accessible to visitors with reduced mobility; the team can provide information in advance. Guide dogs and assistance dogs are admitted into the galleries; other animals are not. The temperature in the galleries does not exceed 10 °C.

Kids & families

• Activity booklet, scavenger hunt or kids’ audio guide

Family rate for 2 adults and 1 to 5 children. An educational booklet to complete during the visit is sold for €1 for children.

Getting there & parking

The fortress lies between Landrethun-le-Nord and Leubringhen, 20 minutes from Boulogne-sur-Mer via the A16 (exit 36) and 20 minutes from Calais via the A16 (exit 38). Signposted route from Marquise, Saint-Inglevert, Landrethun-le-Nord and Leubringhen.

Amenities & dining

• Café
• Museum shop

Area with tables and chairs for a break: cakes, ice cream, hot and cold drinks. Picnic area within the grounds. Shop with local products, souvenirs, books and a guide to the fortress for €4.50.

Events & venue rental

The museum hasn’t published any information on this.

Plan your visit