ENGINEERING & DEFENCE
Arromanches and Longues-sur-Mer: The Harbour and the Guns
The artificial harbour the Allies brought with them, and the only battery in Normandy with its original guns still in place.
See Normandy day trips on GetYourGuide ↗The harbour they towed across the Channel
One of the boldest feats of the whole operation was solving a simple problem: the Allies had captured no port through which to supply the invasion. So they built one in England, towed it across the Channel in pieces, and assembled it off Arromanches in the British sector. 'Port Winston' — named for Churchill — was made of around 115 concrete 'Phoenix' caissons, each six storeys high, together with blockships and floating roadways. In the months after D-Day it landed some 2.5 million men, half a million vehicles and 4 million tons of supplies.
The caissons today
Extraordinarily, the caissons are still there. Great rusting concrete hulks sit on the sand and out in the sea off Arromanches, slowly eroding, visible from the beach and — at low tide — reachable on foot. The town's Arromanches 360 cinema screens archive footage of the Battle of Normandy, and a seafront museum explains how the harbour worked. Many day tours include a stop here; standing among the caissons, the sheer industrial ambition of the invasion becomes tangible in a way the beaches alone don't convey.
The guns at Longues-sur-Mer
Between Omaha and Arromanches stands the Longues-sur-Mer battery, a near-intact piece of the German Atlantic Wall: four 152mm naval guns in their concrete casemates. It is the only battery in Normandy that still holds its original guns, and one of very few places on the coast where you can see the German defences exactly where they stood, still pointing out to the Channel. The guns could throw a 45-kilogram shell more than twenty kilometres.
Why they're worth the stop
The harbour and the battery round out the story the beaches and the cemetery begin. Arromanches shows the astonishing logistics that made the invasion sustainable; Longues-sur-Mer shows what the landing forces were up against. Both are freely accessible, and both are often folded into a day tour's afternoon. If your tour includes them, they're well worth the time — and if choosing a tour, they're a good sign of a fuller, more thoughtful itinerary.