Glapthorn Cow Pastures, Glapthorn, Northamptonshire.
Free public access, with informal free parking along the side of a drive opposite to the access.
An ancient wood on heavy soil. Managed by the Wildlife trust for Bedfordshire, Cambridgeshire and Nothamptonshire.
Large areas of Blackthorn specially managed for the Black Hairstreak.

Personal sightlings:

30 June 2013. 1 Large Skipper, 1 Brimstone, 4 Black Hairstreaks, 1 Red Admiral, 10 Speckled Woods.
1 July 2013. 2 Large Skippers, 1 Green-veined White, 2 Black Hairstreaks, 5 Speckled Woods.