Painted camouflage effects and netting also helped to alter the appearance so that the angular outline of the structure was less obvious. Hooks were incorporated into the sides of hardened defences to attach the nets and hold them in place.
As stated in my blog post dated 08 March 2014, local materials were used in the construction of hardened field defences. Concrete made with stones and pebbles from nearby beaches saved on materials and also enabled structures such as pillboxes and dragons teeth to blend into the local landscape.
In urban areas many pillboxes were designed to appear as though they were part of an existing building, covered with matching brickwork or render and a false roof added. In some cases, pillboxes were even built inside existing buildings. Other pillboxes were constructed to resemble everyday structures such as a bus shelter, shed or garage.
Most of the British wartime defences have now been destroyed. Surviving structures are usually those which were constructed using concrete. Though extremely sturdy, even many of the concrete defences have been lost to coastal erosion, housing developments, road improvements etc. Some pillboxes have been restored and others are in use as storage buildings or cattle sheds on farmland. Other pillboxes which are prone to damp have been converted as roosting sites for bats.
The doorway and embrasures can be left open or pieces of cardboard painted black can be fixed over the back. I blacked out the windows on the N gauge model in case any colours could be seen through the doorway. This was because I used brightly printed cardboard from an old cereal box when constructing the N gauge example.