Butterfly or Moth?

Butterfly or Moth?

Observation - Butterfly or Moth?. Description: Found this at Pen Dinas Nature Resesrve in Aberystwyth. Bought an identification guide but there is nothing that matches. Please, does anyone know what this is.

Found this at Pen Dinas Nature Resesrve in Aberystwyth. Bought an identification guide but there is nothing that matches. Please, does anyone know what this is.