I'm cheating - fireworks aren't that easy to capture. The photograph was manipulated in Photoshop using several series over a period of an hour.

By the way, you're in Dragør harbour, a small fishermans town some 15-16 km. south of Copenhagen, Denmark. The building in the foreground is the old customs house, now occupied by the local sailing club. In the background you may be able to notice the houses of the old town.