I wrote a little bit more about WOŚP (polish huge charity event) here: https://fotshot.wordpress.com/2013/01/13/the-ghost-town/.
But here is why I did come to the city exactly that day. Fire Works weren’t as nice as last years, but it was worth going anyway. I specifically like that type of fire works, which look like golden rain. Here above The Imperial Castle in Poznań. It was constructed in 1910 for William II, German Emperor, with significant input from William himself. Since its completion, the building has housed government offices of Germany (to 1918 and during the Second World War) and Poland (1918–1939, after 1945).