The Channel Islands were strongest in terms of a Naval perspective. This facilitated the construction of 3 Naval Batteries with more planned but never finished. Instead, temporary Army Coastal Batteries were erected.
Steinbruch has been almost entirely destroyed, with only a few remaining structures. It is located as Les Vardes quarry.
Strassburg is in a good state of preservation in Jerbourg. Plans to build a house on an Ammunition bunker rejected recently.
Mirus is the largest, mounting 30.5cm cannons that defended the island. Range of some 46km. Site survives well.