St Mary sub Castro, Dover

St Mary sub Castro stands inside the outer walls of Dover Castle on the Eastern Heights above the White Cliffs. It is an Anglo-Saxon church built around the year 1000 beside the remains of a Roman lighthouse that now serves as its bell-tower. The building is cruciform with a central tower, plain nave without aisles, and an early English vault added in the late 12th century. Roman tiles and flints taken from the lighthouse are built into the walls and window arches. The south door arch is the earliest surviving example in any standing English church. The church has been repaired and altered many times since the 13th century. Henry III ordered work on the church in 1226 and 1247, and new bells were cast at Canterbury in 1345. Between 1426 and 1437 the lighthouse stage was rebuilt with five new windows at a cost of £176. It was walled up in 1555, repaired in 1582, and later used as a storehouse and coal store. Two Victorian restorations in 1860–62 and 1888 returned the church to worship. Visitors find a small but historic interior. The crossing arches are original, the blocked south door shows Anglo-Saxon stripwork, and the nave walls contain double-splayed windows. William Butterfield’s 1888 restoration added mosaic floors and a vestry. The church remains in use for garrison services and local worship, overlooked by the castle’s main tower.