Last month, I met with a good friend of mine who I haven't seen in a long time. She happened to be in Berlin for a bit, and had an apartment in Kreuzberg. It was May 1st, and I had no idea it was going to be wild.
The thing is, apparently, May First in Kreuzberg is a big thing. It's when the whole neighborhood turns into a street party. Kreuzberg, especially the area known as SO36, is the epicenter for the whole counter-culture and punk movement, so there are plenty of anarchists and similar types. If you go to the Wikipedia article on May Day in Kreuzberg, then you'll see that there's history on this topic. Apparently, there was a year in which policemen actually had a retreat for several hours against the counter-culture radicals.
Anyway, I had no idea this was happening. Instead, what we saw were brigades of policemen everywhere, and anarchist flyers and pamphlets. There were barbecues, and street food, and a stage where DJs and bands were playing, almost at every corner. It was interesting. It's like everyone living in Berlin from ages 18 to 36 were there. And the proportion of people who had their hair dyed was really high.
I usually do not do well with crowds, so I had to find shortcuts and other side streets to avoid them, but overall, it was still an interesting experience. I probably won't do it again next year though.