While visiting Stockholm, Sweden recently I was pleasantly surprised to come across first-calendar year Common Gulls Larus canus in (almost) full juvenile plumage.
They were very tame (reminiscent of the Black-headed Gulls that we have over here in winter) and gave plenty of opportunity to photograph them in ways that I never encounter over here in the Netherlands.
(Sub-)Adults were mostly absent.
All photos were taken around the Skeppsbronn area, 7-10 August 2015.
With a faint mirror on P10:
Gulls to the Horizon 