North of Deal, on the coast of Kent, Sandown Castle is the third and most unfortunate of Henry VIII's twin forts. Where Deal and Walmer still raise their intact bastions, Sandown is now only an outcrop of stone caught in the concrete of a sea wall — the razed memory of one and the same defensive ambition.
The third lock of the Downs
Sandown was built in 1539-1540, at the same time as Deal and Walmer, as part of Henry VIII's 'Device programme': these three artillery forts, aligned along the coast, were to forbid any enemy landing at the strategic anchorage of the Downs, against the threat of a Franco-Imperial invasion. Sandown shared the architecture of its twins — central keep and rounded bastions, bristling with guns — and completed, to the north, the arrangement that Walmer closed to the south and Deal held in the centre.
A razed destiny
Sandown's fate was cruelly different from that of its brothers. After playing a role in the Second Civil War (Royalist seizure of 1648-49; Colonel John Hutchinson was later held here and died here in 1664), the fort, eaten by the sea, was judged useless. In 1863, the War Office demolished its upper levels. Only the lower levels of the keep and bastions survive today, cased in 1988-89 in the concrete of the sea wall. Sandown thus illustrates the unequal fate of the three forts: two preserved, one effaced. To see: the remains of the lower levels integrated into the coastal defences of Deal (a scheduled monument since 1960).
Did you know?
Henry VIII's three twin forts — Deal, Walmer, Sandown — have known three destinies: two can still be visited intact, the third has almost vanished. Razed by the War Office in 1863 then gnawed by the sea, Sandown shows only its foundations, poured into the concrete of a sea wall in 1988. Of one and the same family of stone, it is the effaced brother.
Notes
Sandown Castle lies at Sandown, north of Deal, Kent; razed remains integrated into the seafront, an open and freely accessible site (a scheduled monument). A memorial area rather than a visitable castle.
Quiz
- To which group of forts does Sandown belong?
- The three twin forts of the Downs (with Deal and Walmer)
- The Welsh castles of Edward I
- The Channel Device Forts only
- What remains of Sandown today?
- Its lower levels cased in concrete
- The intact keep
- Nothing at all
- When were its upper levels demolished?
- In 1863, by the War Office
- In 1540
- Never

