Our Saxon ancestors, on surveying this strange pot-marked heath land, would refer to the site as 'The devils holes of the god Grim', and that is how the unusual name of 'Grimes Graves' arose for these Stone Age, backfilled flint mines. Flint was an important commodity to those early peoples as it provided a hard, but workable, material for the production of tools and weapons. The flint nodules, having a glass-like fracture quality, could be 'knapped' (chipped) to give a fine, razor sharp cutting edge.
It was probably around 2100BC that the Grimes Graves mines were first opened, and they consisted of a tapering vertical shaft that would be cut to various depths, maybe as deep as 30-40ft (10m-12.5m), with surface openings anything between 13ft to 26ft (4m-8m). By the time production stopped, there were some 360 shafts of this type, which have since backfilled to give the landscape its distinct crater-like surface.
There are three flint seams running through the chalk strata in this area, and the shafts contained these at roughly the top, middle and bottom levels. However, it was the bottom layer of high quality flint that was the main object of their arduous labours. Once the shaft had been dug to the base level seam, the flint would be mined by working out from the centre of the shaft to form a series of radiating galleries. As the shafts were in very close proximity to each other, the galleries would eventually join up with adjacent galleries, forming a labyrinth of narrow cramped tunnels.
The prime mining tool, used in the abstraction of the flint, was the bone antler of the Red Deer, which the animals shed each year. These antlers are very hard, and when trimmed make a very efficient right-angled axe. An interesting fact arising from Stone Age use of the antlers is that they appear to have had a good understanding of resource management, because if too many deer were killed for food, it would have had a detrimental effect on the antler stock in the following year. It has been estimated that a herd of 120 deer would have facilitated sufficient antler bone to allow one, maybe two, pits to have been opened every year. Mining at the site appears to have ceased around 1650BC.
Now managed by English Heritage, one of the excavated shafts at Grimes Graves has been opened to the public. With a protective entrance building covering the site, and a steel ladder allowing secure access to the shaft floor, it is possible to see the top and middle flint seam quite clearly in the shaft walls. At the bottom of the shaft the radiating galleries have been illuminated to allow visitors to see into them, but access has been restricted for obvious safety reasons.
I found the whole experience very different, and quite thought-provoking as I tried to imagine our primitive ancestors on their hands and knees, scraping around in the dark depths of this inhospitable 'hole-in-the-ground' for hours each day. They must have wanted the flint pretty badly because it would have taken some major enticement to get me down there more than once!