Along the coast look out for the fortifications built to protect Britain against German invasion in World War II. Begun after the evacuation at Dunkirk the 'Coastal Crust' as it was called, was designed as first line of defence against invasion; it involved many types of structure, some of which can still be seen - pillboxes, searchlight batteries, anti-tank structures and machine gun posts. During the war gun emplacements were camouflaged as bungalows, ice-cream parlours or chicken sheds and linear marks bisecting fields are probably anti-landing trenches dug to prevent aircraft landing. Much survives along Lincolnshire's coast as an evocative reminder of the desperate days of 1940. Defences can be found at Frampton Marsh and Freiston Shore. These concrete remains, even a pill box in a peaceful churchyard, are recent history and give the landscape added meaning.