EROSION of Suffolk's crumbling coastline is threatening its military history.Over the years, Martello Towers, a castle, pillboxes, machine gun posts and other buildings have been lost to the sea.

EROSION of Suffolk's crumbling coastline is threatening its military history.

Over the years, Martello Towers, a castle, pillboxes, machine gun posts and other buildings have been lost to the sea.

Now a new book has been published which looks at the battle to defend the Suffolk coast from enemy invasion, but also highlights the increasing threat that much of its heritage still faces.

Launching the English Heritage book Suffolk's Defended Shore at Felixstowe's Landguard Fort, authors Cain Hegarty and Sarah Newsome said their aim was to highlight the coast's military history as well as the threat to fortifications.

“One of the reasons for doing the book was so people walking along Suffolk's shore and walking past these military structures would understand their significance, both nationally and in terms of world events,” said Mr Hegarty.

England's coast is in places being eroded by an average one metre per year and, as a result, it is estimated many thousands of historical sites and buildings are under threat of being literally washed out to sea.

Felixstowe lost a Martello Tower to erosion when the Napoleonic fort was washed away from the beach just 20 years after it was built. Walton Castle, a Roman fort which stood at The Dip to defend the province against the attack of bands of Germanic and Scandinavian pirates, was lost to the sea by the mid-18th century.

Other monuments have been lost to other forces - Dooley Fort was demolished to make way for port expansion.

Further up the coast, the battle to protect Slaughden Martello Tower near Aldeburgh is ongoing with its moat lost over the past 60 years and the sea now dangerously close to the building.

“Places like Landguard Fort will not be lost to the sea because they are so well protected, but as you walk along the coast you can see structures like pillboxes disappearing - there may be one on the clifftop, one halfway down the cliff and another already smashed and in the sea,” said Miss Newsome.

The pair started research on the project six years ago and have made great use of the National Mapping Programme - a countrywide survey commissioned by English Heritage, examining aerial photographs, largely from World War Two to the present, which can inform historians and archaeologists of historical sites no longer visible or accessible from the ground.

“The photographs provide us with a valuable tool for the study of Suffolk's coast,” said Miss Newsome.

“They provide a different, and often unique, perspective on military defences, particularly those constructed in World War Two.

“Photographs taken during and immediately after this war sometimes provide the only visual record of the rapidly evolving defences from this period.”

Suffolk's Defended Shore is available from bookshops and English Heritage monuments, priced at £14.99.