There are many 20th-century defensive structures dotted around the countryside and coast of Northern Ireland. These include trenches, gun and search emplacements, pillboxes, observation posts, airfields, harbours, naval and flying boat bases, air raid shelters, and many other interesting structures.
The majority of these are derelict, some have been reused or altered, others are in a state of decay. Many have been demolished or destroyed.
A small number of dedicated volunteers have amassed an impressive record of many aspects of this heritage, but the coverage is not yet complete. In the absence of a full survey, how can their significance be evaluated? How can we decide which ones merit preservation?
As a result of these concerns, The Defence of Britain Project was launched. Co-ordinated by the Council for British Archaeology (CBA), recording work was undertaken by volunteers. Two years later Northern Ireland joined the project with the Defence Heritage Project (DHP). Environment and Heritage Service (EHS) co-ordinates and stores all records on the DHP database, and sends copies of all site records to the Defence of Britain Project, where they are integrated into their database. These records can be viewed on their web site (www.britarch.ac.uk/projects/dob) 
The DHP is always interested in hearing from people with an interest in 20th-century defence, particularly those willing to join our volunteers.
Contact:
Tel: (028) 9054 3009 or
e-mail: hm@doeni.gov.uk