Martello towers were built to protect the vulnerable sluices that controlled the water level in the canal, being towers numbers 22 to 27 and 30, three of which are still standing. Peacetime use Despite the fact that the canal never saw military action, it was used to try to control smuggling from Romney Marsh. Guard houses were constructed at each bridge along its length. This met with limited success because of corrupt guards. Although a barge service was established from Hythe to Rye, the canal was abandoned in 1877 and leased to the Lords of the Level of Romney Marsh. World War II During the early stages of World War II, during preparations for a threatened German invasion, the canal was manned by 31st Independent Brigade Group, who fortified each salient with a concrete pillbox and barbed wire entanglements; numerous pillboxes survive today. In the German invasion plan, codenamed Operation Sea Lion, the paratroopers of the 7th Flieger-Division were tasked with a parachute landing to secure crossing points across the Royal Military Canal on the first day of the invasion. The canal today A public path runs alongside the entire length of the canal, forming part of the longer Saxon Shore Way. Aside from being historically significant in its own right, the path passes by numerous WW II pillboxes and the unusual acoustic mirrors, the historic cinque port towns of Hythe, Winchelsea, and Rye, the 12th century St Rumwold's church, and Lympne and Camber castles. The canal is an important environmental site, and passes through several Sites of Special Scientific Interest. The Environment Agency is the navigation authority and uses the waterway to manage water levels on Romney Marsh and Walland Marsh. It is important for fish and other wildlife, including kingfishers, dragonflies, and marsh frogs. See also Canals of the United Kingdom History of the British canal system British anti-invasion preparations of 1803–1805 References Bibliography External links The Canal page at the Romney Marsh Countryside Project website images & map of mile markers seen along the Royal Military canal History of Kent Napoleon's planned invasion of the United Kingdom Fortification lines Canals in Kent Canals opened in 1809