The Martello Tower at Aldeburgh in Suffolk. 103 of these towers were built along the south and east coast of England between 1805 and 1812, to resist a potential attack by Napoleon (which never happened!). This one is the largest and most northerly of them, and was built in 1810-1812 in a quatrefoil shape (most are round), it stands about 40ft tall with the sea-facing walls around 13ft thick - nearly a million bricks were used in its construction! Only 45 of these towers still remain, but many are in ruins or have been converted; only 9 remain in their original condition.