Natural England - Grime's Graves (SSSI)
Grime's Graves (SSSI)
Location and Access Information
Grid Reference: TL 815900
Grime's Graves is located 10km north-west of Thetford off the A134. The site of the flint mining caves is owned and managed by English Heritage and there is open access to the surrounding land. Car parking is available at the site.
View the site map on Nature on the Map.
Geological Interest
Named Grim's Graves by the Anglo-Saxons after the pagan god Grim, this area of Breckland heath is an old area of mines dug some 4,000 years ago to obtain good quality flint for the production of tools and weapons. One of the mines has been re-excavated and is open to the public. The surrounding heathland area has many of the characteristic features of a Breckland 'Heath'. There is a wide range of plant communities, each in close proximity to one another, reflecting differences in management and soil type. Heather heathland is found in the northern part of the site, where it is arranged in a series of parallel stripes which alternate with bands of acidic grassland. This pattern reflects differences in the composition of the underlying soil which is due to the sorting of the sediment by freeze-thaw during the arctic conditions of the last ice age (the Devensian Glaciation) some 10,000-50,000 years ago. A trench in the north-western part of the heath shows a cross-section through the stripes.