Owing to historic coastal erosion, the church ruins are now on the edge of a cliff. They form a backdrop to wide Thames-side marshes, and are sited within the remains of the Roman, Saxon Shore fort. Called "Regulbium", the fort guarded the north end of what were then the broad waters of the Wantsum Channel, which separated the Isle of Thanet from the rest of Kent, and was open to shipping. Recent archaeological excavation has shown that the site had been occupied in pre-historic times, and it is of interest that the name "Regulbium" is Celtic in origin, probably meaning "at the promontory", or similar. The place is elevated above the surrounding countryside, and it still sits on a slight promontory today. In Old English, the place-name became corrupted to "Raculf", ultimately giving rise to the modern "Reculver".
While the churchyard to the north of the church has long since been lost to the sea, together with a large proportion of the Roman fort, Reculver continues to be threatened by the retreating coastline. The cliffs between Reculver and Herne Bay, which rise up to 30 metres (98 ft) in height, are highly vulnerable to erosion since they are composed of soft sand and clays, originally laid down in shallow seas about 60 million years ago. Consequently the coastline is receding extremely quickly, threatening residents and the local tourism industry. At present the area remains inadequately protected, and the provision of adequate sea defences is still under debate.