Butterflies are not easy to photograph in close-up unless you have a telephoto lens (which I don't). Here is as close as I could get to this Gatekeeper in a spot that had all of its habitat characteristics. 

 It alighted on a Yew hedge- this species is also known as the Hedge Brown. It was indeed near a gate, or in this case an opening where the path leads through the hedge. The Butterfly Conservation website notes that the Gatekeeper is "often encountered where clumps of flowers grow in gateways and along hedgerows and field margins". Sure enough there were clumps of flowers right by the gate and along the hedge.