Holly Blues (Celastrina argiolus) are apparently quite common here in Sweden but this is the first time I've seen one myself. It perched on a Wood Anemone (Anemone nemorosa) long enough for me to get a photo, which I thought was very nice of it!
I was very excited this weekend to have gotten some of the best macro shots I've ever taken of a holly blue butterfly in my garden! They are tiny and infrequently settle at eye level so this was a treat.