Devil's Dyke, Cambridgeshire.
An ancient defensive barrier across the chalk over Newmarket Heath to the edge of the Fens.
It is a public footpath with access at all times from each end and from a car park between Swaffham Prior and Burwell.
From April 1994 part of Newmarket Heath, including the Beacon Course, up to the side of the Devils Dyke was transfered from Cambridgeshire to Suffolk.
Current Ordnance Survey maps show the border following the public footpath along the top of the ridge, with the north-east slope of that section in Suffolk.
The Devils Dyke is known for its populations Dingy Skippers, Chalkhill Blues and Green Hairstreaks. There can also be some spectacular displays from
large numbers of Brimstones in season.
Wikipedia entry .
Note: the current OS map shows the Cambs/Suffolk border as running across Newmarket Heath along the top of the dyke.
10 April 2011. Reach end, Burwell Cutting. Numerous Brimstones, 6 Green Hairstreaks, 1 Speckled Wood.
3 July 2011. Newmarket Heath. 6 Chalkhill Blues, 1 Marbled White.
15 July 2011. Newmarket Heath. Many Chalkhill Blues.
31 July 2011. Reach end. Early to mid afternoon, bright intervals, windy. 1 Brimstone, many Chalkhill Blues, 2 Brown Argus, 1 Small Heath, several Gatekeepers,
few Meadow Browns.
7 Aug 2011. Essex and Cambs Branch field walk. Fairly bright, windy. Newmarket Heath, c. 30 Chalkhill Blues; Golf Course end, c. 10 Chalkhill Blues.
3 Sept 2011. Sunny, windy. Newmarket Heath. 20-30 Chalkhill Blues all very worn - none were seen to be male. 2 Small Heaths.
25 March 2012. Reach end, near Burwell Railway cutting. TL575652. 3 Peacocks on male Sallow flowers.
12 May 2012. Newmarket Heath. TL614618, 6 Dingy Skippers. By the Golf course near the further Tee (No 15), TL 624609, 2 Dingy Skippers, 1 Brimstone,
1 Green Hairstreak, 3 Small Tort,
25 May 2012. Newmarket Heath. TL614618, 2 Dingy Skippers, 3 Orange Tips, 3 Brimstones, 2 Green Hairstreaks, 6 Brown Argus, 3 Small Heaths.
Golf Course end. TL 625609. 2 Brimstones, 1 Green Hairstreak, 2 Brown Argus, 3 Small Heaths.
15 Sept. 2012. Newmarket heath. TL614618. 3 Small Whites, 1 Small Copper, 2 Brown Argus, 1 Common Blue, 7 Chalkhill Blues, 1 Comma, 1 Meadow Brown,
9 Small Heaths. 1 Silver Y.
15 Sept 2012. TL5765. In and near Burwell Railway cutting. 5 Chalkhill Blues, 2 Red Admirals, 1 Comma, 1 Speckled Wood, 1 Small Heath.