For the sheer number and variety of accessible bunkers, casemates, and concrete positions, the Neville Blankenese site - also known as Batterie de Carqueret - on the North East coast of the Cotentin peninsula is a must-visit location for bunker hunters.
This site - codenamed Wn126 - was built around four British Vickers 94mm anti-aircraft guns captured during the occupation of the Channel Islands and protected the coast in this area between Cherbourg and Gatteville.

You can access the inside of many of the buildings (with care!) and also crawl through covered concrete trenches which linked the casemates, ammunition bunkers, personnel shelters, anti-aircraft gun position, a searchlight stand, and multiple machine gun Tobruks and bunkers.

The site once featured a special construction observation and Fire Control Post at the tip of the point of land but this has been destroyed by a huge explosion. The same can also be said for three of the four casemates built for the guns, although they seem to have stood up to the attempted demolition by US Engineers much better than the FCP.
The casemates are a mix of styles with a Kriegsmarine M272 type casemate and an early, open emplacement style M158 casemate to the east of the site while the front and western gun positions were of a special construction design.

In the centre of the site, behind the gun casemates and FCP you'll find plenty of other structures including a huge M151 bunker which originally featured seven rooms for officers and around 24 soldiers stationed at the coastal batterie. Today the inside is pretty much destroyed but you can still make out the individual areas where the troops who manned the gun bunkers here would have lived.
At the western end of the site there are several areas where you can see evidence of the soldiers stationed here as they must have walked across one of the tunnel roofs before the concrete had set and there are imprints of their boots visible.

To the rear, along with a series of defensive Tobruks and a sentry post bunker covering the entrance road, you can also find the remains of an original piggery, toilet block, and sluice gate - something we haven't seen at any other site in the area.
This site is heavily used by the local 'artists' and their work on the walls of the concrete seems to be altered every couple of months.