Castle and cathedral stand close together beside the River Medway. For once, it is the castle, which dominates, the squat cathedral tower seeming insignificant alongside the magnificent keep. This is the tallest of the Norman keeps, rising 115 feet to the top of its corner turrets.
Archbishop Corbeil’s keep is intact save for the loss of its roof and floors. A relatively small floor area accentuates the height; small that is when compared with an immense cuboid such as Dover. The keep is five stages high, including the double story, which contained the hall and solar. Originally, the only entrance was at first floor level via a fore building.
The fore building is a tall and narrow projection, higher than most fore buildings, though it does not rise the full height of the keep. It contains a vaulted prison chamber beneath the entrance vestibule and an austere chapel, which was reached from the body of the keep, above it. At this level, the cross wall is pierced by a four-bay arcade.
In the middle of the cross wall, a well shaft rises the full height of the keep so that water could be drawn at each level. Rochester is one of those ambitious keeps with a mural gallery at the upper level around the hall and solar. The windows here are unusually large for a Norman keep – presumably at this height they were considered to be out of reach of siege towers. The top floor above the gallery level, also well lit, is a luxury matched among Norman keeps only at Hedingham Castle, which may have been designed by the same architect.
Three of the corner turrets, rising well above parapet level, are square, but the south corner turret is circular. This whole corner belongs to Henry III’s reconstruction after the siege of 1215.