Flat Holm Victorian Rock Cut Defensive Ditch and Rampart

Cadw's description

Summary description and reason for designation

The monument comprises the well preserved remains of a Victorian defensive ditch and bank, which was constructed to defend the military garrison that occupied Flat Holm Island in the Bristol Channel. The island’s gun batteries were constructed between 1866-71, and it is thought that the defensive bank and ditch were constructed at the same time. They are located on the south-east corner of the island and extend west from just north of Dripping Cove before striking south to enclose c. 1.5 ha of land around Lighthouse Point. The ditch is flat-bottomed and almost sheer-sided. The north alignment measures c. 80m in length. The west alignment measures c. 183m in length NNE-SSW. The ditch measures up to 8m in width and 6m in depth. The associated defensive bank sits immediately behind the ditch and measures 5m in width and between 2-3.5m in height. The ditch was used during the Second World War to hide engine rooms, water tanks and other buildings, the remains of which still survive.

The monument is of national importance for its potential to enhance our knowledge of the defensive practices of the British Army during the Victorian period. It was common practice for the War Department to enclose garrison artillery with defensive ditches and banks, and this is a particularly good example. The monument is well-preserved and retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits, relating to chronology, building techniques and architectural detail. The bank and ditch was functionally inter-dependent with the barracks and gun batteries elsewhere on the island and possesses important group value with these designated assets.

The scheduled area comprises the remains described and an area around within which related evidence may be expected to survive. The scheduled area is an irregular L-shaped polygon. It is centred on OS NGR 322183 164713 and measures c. 270m in length NNE-SSW by 24m in width.