From the National Heritage List for England: Details The monument includes the best surviving stretch of the medieval canal known as the Rhee Wall, situated along the interface between the lower lying ground of Walland Marsh to the south west and Romney Marsh to the north east. The canal originally ran for a total length of 7.5 miles between New Romney, then one of the Cinque Ports, and the inland town of Appledore. It was constructed during the mid-13th century in order to help flush out the rapidly silting harbour at Romney Creek by redirecting sea water towards the port from further up the River Rother estuary, and to provide a shipping channel between the two settlements. The monument lies towards the north western end of the canal and survives in the form of earthworks and buried remains. The central feature is a substantial water channel up to c.50m wide, the meandering course of which indicates that the canal's engineers utilised a natural watercourse at this point. This channel has become infilled over the years, and has also been partially disturbed by the construction of a modern bungalow, outbuildings, land drains and pond, but survives in buried form between two retaining banks. The south westerly of these is up to 17m wide and survives to a height of up to 2m above the lower ground to the south west. A slight berm c.7m wide runs alongside the south western edge of the bank. Subsequent drain digging and agricultural activity has breached the bank in several places. The course of the north easterly retaining bank is followed by the modern B2080, which runs along a raised causeway, and partial excavation around 3km to the south east of the monument at Brenzett has indicated that the bank may survive within the causeway in partially disturbed, residual form. The excavations showed the canal banks to be constructed of dumped local silty clays and sand. During the great storms of 1287-8, the Rhee Wall helped protect the reclaimed marshes to the north from the flooding which devasted much of Walland Marsh, and the ports of Romney, to the south. The canal, which was always prone to silting, fell into disuse as a shipping route during the 15th century, although its dry, raised banks continued to be used as an overland trade route across the marshes. The section of the canal between Appledore and Snargate, of which the monument forms a part, acted as the main drain for the south westerly marshes until 1544, when a new gutt was made at Arrowhead. The modern bungalow, all modern outbuildings, sheds, fences and gates, and the modern surfaces of all roads, yards, tracks and paths are excluded from the scheduling, although the ground beneath all these features is included. Reasons for Designation The use of inland water routes, along with coastal navigation, formed the main means of transport and long distance internal trade during the medieval period, prior to the building of an adequate road network. However, the construction of canals to supplement river transport was an uncommon practice, demanding a high expenditure of time and labour. Very few examples of this monument type are known to have survived to the present day. The section of the Rhee Wall at Snargate survives relatively well and will contain archaeological remains and environmental evidence relating to the canal and the landscape in which it was constructed and used. Conditions within the infilled water channel can be expected to preserve organic material. The construction and subsequent history of the monument is comparatively well documented by surviving contemporary records, supplemented by recent partial excavation. Its construction illustrates the struggle for existence by the channel ports against natural coastal processes during the later medieval period, and the substantial nature and dual purpose of the monument as a harbour-flushing device and transport route reflects the importance of trade and inland water transport to this area of Kent during the later medieval period.