9 Dunwich

Grid reference [TM 478 705]

Dunwich today is a small, tranquil village overlooking the sea and a wide expanse of grazing marshes fronted by a barrier beach. In the early Middle Ages it was one of the most important North Sea trading ports.

There was an estuary where Dingle Marshes now lie, and ships could anchor in the lee of a shingle spit known as Kingsholm. However a series of storms in the late 13th and early 14th centuries rearranged the coastal geography, blocking the entrance to the port and progressively destroying wide areas of the city.

Since then the coast has retreated at an average rate of 1 m (3.3 ft) per year, although the rate has slowed up over the last 50 years; shifting offshore sand banks may be part of the explanation.

Today, geotextile bolsters and gabions buried in the beach are helping to stabilise the cliffs and so protect what is left of Dunwich. A diorama model at Dunwich Museum graphically explains the erosion story, and the last buttress from the tower of All Saints Church, now vanished, has been re- erected in St James’s churchyard; masonry from the lost city can be seen recycled in local walls. Recently, the University of Southampton has used remote surveying techniques to map the city’s underwater extent.

Visitors wishing to see remote prehistory should visit the cliffs at Dunwich Heath. Here the flint- rich Westleton Beds of the Norwich Crag Formation are dramatically displayed. About 1.8 million years ago a complex of sand and gravel bodies were laid down in a wave-dominated, gravelly shoreface environment similar to the present day. In places broad, saucer-shaped gravel bodies can be seen cutting into underlying beds; these are evidence of underwater rip channels transporting beach material offshore. The coastline was evidently nearby at the time. It is also worth a trip inland to see the Westleton Beds displayed at St Helena’s Pit in Dunwich Forest or in the old pits on Westleton Heath.

Figure

(Figure 26) An artist’s impression of a map of old Dunwich 1587, from a lantern slide by AR Fisk, c.1910. The old harbour has been blocked by shingle. The red dotted line shows the line of the present coast. © Trustees of Dunwich Museum.

(Figure 27) The Westleton Beds at Dunwich Heath cliffs