At the far north western end of the outer curtain wall of Dover Castle is a group of five towers which once formed the north entrance to the castle. Two of these were originally constructed late in the reign of King John (1199-1216) but were blocked and substantially rebuilt after the French siege in 1216/17 and new towers were constructed on their eastern side. Two new entrances were created in less vulnerable locations (Fitzwilliam and constables gates). The towers were later modified to carry a Napoleonic battery.

The easternmost tower is round with a battered base very similar to that of the Crevecoeur Tower, and is not obviously a post-siege replacement. The former gate consists of two round towers with battered bases, the right (W) one with loops regarded as an original tower, and the left one (much ivy covered) largely rebuilt after its collapse in the siege. The mass of masonry blocking the former entry between the towers is a pointed beak advancing from two curved walls that emerge from the curve of the flanking towers. Behind and beneath the Norfolk Towers are the remains of tunnels – mines and counter-mines – dating from the time of the siege. The principal tunnel immediately post-dates the siege when it was constructed as part of a scheme to allow the garrison covered access to the new northern defences. (summarised from reports) (1-2)

<1> English Heritage, 2014, Dover Castle Conservation Management Plan Volume 2 Gazetteer (Unpublished document). SKE52105.

<2> Johnathan Coad, 1995, English Heritage Book of Dover Castle and the Defences of Dover (Monograph). SKE52106.