List entry Description Summary of Monument A 700m length of the Royal Military Canal from West Hythe Dam to West Hythe Bridge. Reasons for Designation The Royal Military Canal was a massive coastal defence work constructed between 1804 and 1809. Its purpose was to separate the expected landing and deployment of Napoleon's troops upon the coast of Romney Marsh and Walland Marsh from the interior of the country. The Government initially considered flooding the marsh but favoured the canal, which was the idea of Lt. Col. Brown, the Assistant Quartermaster-General. He carried out a survey and work commenced in 1804 at the height of the invasion scare, with John Rennie as consulting engineer (until 1805). The canal ran a total of about 28 miles from Shorncliffe Camp via Hythe inland to Appledore, to join the Eastern River Rother at Iden lock, from where it became part of first the Rother and then the River Brede, turning into a canal again from Winchelsea to Cliff End on the coast. Excavated earth formed the banquette and parapet on the landward side of the canal and behind this was an army supply route, the Royal Military Road. On the opposite side were the tow path and wharves. It also included a back and a front drain. The canal and parapets were so built that gun positions could be provided at the end of each length to flank the crossings. However by the time the canal was completed in 1809, the threat of invasion had passed, following Napoleon’s defeat at the Battle of Trafalgar, and it was to some extent obsolete. In 1810, the canal was opened for public use and tolls were also collected for use of the Royal Military Road. In the later 19th century public use declined. The last toll was collected at Iden Lock in December 1909. Today Iden lock is a sluice, so the main part of the canal is isolated. The eastern section of the canal is still in use for pleasure boats. The Royal Military Canal was an important element in the Napoleonic defences of south-east England and is the only military canal in the country. It is a unique defensive work that bears significant testament to a period when modern Britain faced the most serious threat of invasion prior to the major conflicts of the 20th century. The 700m length of the Royal Military Canal from West Hythe Dam to West Hythe Bridge survives well. It includes some well preserved original features such as the parapet, the Royal Military Road and the back drain. The canal will contain archaeological information relating to its construction and use. History See Details. Details This record was the subject of a minor enhancement on 31 July 2014. The record has been generated from an "old county number" (OCN) scheduling record. These are monuments that were not reviewed under the Monuments Protection Programme and are some of our oldest designation records. The monument includes a length of the Royal Military Canal, an early 19th century defensive work, situated on low-lying ground on Romney Marsh, south of Lympne. It runs ENE from West Hythe Dam for 570m before turning to the east for the remaining 130m to West Hythe Bridge. The length of canal is water-filled and the surviving features include the parapet, a bank on the north side, the Royal Military Road which survives as an earthen terrace, and the back drain, which survives as a ditch.