I found this quite large butterfly enjoying the sun shine on the gravel near Kaitalampi pond in Nuuksio national park.The wingspan was approximately 9 cm and the forewings were bluish black with no particular pattern on them. Never seen this kind of butterfly and I couldn't identify it from the books either. Looks very much like Limenitis populi though except there isn't any patterns on the forewings which is typical for Poplar admiral.
