Here is a series of bunkers which largely go under the radar for visitors to Normandy. This is the Erika II radar station in St Pierre Église to the east of Cherbourg on the northern Cotentin peninsula.

Hidden behind tall hedgerows away from passing travellers, there are six installations here for the late-war, long-range, radio guidance system plus two generator and command bunkers - one of which is being developed and refurbished inside.
The six radio bunkers are on private farm land and not accessible but the command bunker is open a few days each year for visitors. More info at www.erika2.com

This site was one of only two built in France - the first one was constructed at Equihen, just to the south of Boulogne-sur-Mer in the Pas de Calais region. Together they were designed to direct bombing missions over England but came so late in the war that the allies had almost complete aerial superiority and so we largely on borrowed time before being captured as the allies moved across the Cotentin towards Cherbourg.