In recent years this butterfly went into rapid decline. I haven’t seen it at all for a couple of years. At the moment there is an influx of these butterflies from the continent, and this morning there was one on the Buddleia near the Church Street entrance. Although it hasn’t opened its wings for me, this is definitely a Small Tortoiseshell, Aglais urticae. (Urtica dioica is the latin name for nettle, which the caterpillars of this species feed on). Link to photos of Butterflies in Abney.
Small Tortoiseshell Butterfly
Abney Fungi 