Summarised from report:

The North Entrance to the Western Heights was situated at a narrow point of the ridge towards the north-eastern end of the fortress, where the North Military Road completed its more moderate ascent from Dover town. The earliest phase of works on this entrance dates to the Napoleonic period, but further work on the North Entrance to complete and modernise it began in in March 1860 and it was finished by February 1864. This created a more elaborate defensive scheme and perhaps reflects a greater concern with a potential assault from the north. A tunnel was constructed as part of these 1860’s works between the inner and the outer entrance.

This semi-circular-vaulted tunnel follows an elongated ‘S’-shaped course as a defensive measure against ricochet. The road surface was formed from large pine blocks, each 16cm square, set in tar between granite kerbs, though many have been robbed out. Ventilation and some light for the tunnel are provided by a single elliptical-cone shaped shaft rising vertically from the top of the vault; a magnificent piece of brickwork closed at the top by an iron grille. A pair of heavy sliding wooden doors form an inner gate which enabled the entrance chamber and the bridge to be closed off from the tunnel. The doors are strongly constructed with raked boarding and rise to the full height of the tunnel entrance with the tops shaped to fit against the vault. Immediately beyond these doors, the western wall of the tunnel contains an entrance onto steps leading down to the postern gate. (1)

Parts of this tunnel are depicted on a plan dating to 1861 suggesting that it was one of the first features to be constructed under the 1860's scheme of work. (2)

<1> RCHME, 2000, The Western Heights, Dover, Kent. Report No 6: The Entrances to the Fortress: 19th-century artillery fortifications (Unpublished document). SKE17501.

<2> Office of Works, 1861, Plan and section of the North Centre Bastion and the North Entrance of the Western Heights. (Plan). SKE51621.