The Annexe level wartime tunnels at Dover Castle were constructed in 1941-1942 as a medical dressing station and as accommodation for the CHQ. It is situated to the west of the Officers New barracks, at the southern end of the Castle Complex and is below the earlier Casemate level tunnels.

The main access point apart from this staircase is the main entrance to the west which leads onto Knights Road. A further access point to the tunnels is via an earlier (1856) spiral staircase at its north eastern end. The tunnels were constructed on a simple grid system with three roughly east/ west galleries, the north and south ones of which are divided into smaller areas. There are two sets of eight tunnels lying between the north and south galleries and separated by a central gallery, which were formerly predominantly used as wards and dormitories. Annexe Level uses the same construction method as Dumpy Level and reflects its Second World War build, including a curved roof lined with arcuate sheeting supported on metal braces with a concrete floor. Generally extant fixtures and fittings include lighting, air vents and wooden doors dating from the Second World War and Cold War periods. Brick is used in areas (for example in providing a base for the arcuate sheeting, or as partitions) as are breeze blocks, the latter relating to the Cold War use of the site. Summarised from sources (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 English Heritage, 2014, Dover Castle Conservation Management Plan Volume 2 Gazetteer (Unpublished document).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.