The Isles of Scilly are renowned for their natural beauty, wild flowers and temperate climate, but there is another reason to visit these paradise islands. Since the 16th century they have been in the frontline of this country’s military defences and successive generations of fortifications have survived in Scilly, unmatched in any other location around Britain. This unrivalled survival was due to the lack of pressure to develop the islands and happily because the feared enemy rarely attacked. However, there is another threat to this precious heritage, the power of the sea. William Borlase in the mid-18th century recorded how much of the islands’ history had succumbed to rising sea level, and today increasingly turbulent weather patterns may be accelerating the process of coastal erosion. This book celebrates the unique survival of military fortifications on the islands, but it also serves to illustrate the value and vulnerability of the whole country’s coastal heritage. Like King Canute, we cannot turn back the sea, but we can celebrate these precious survivals from the colourful history of our island nation.