This happens every Friday to Saturday night and also Saturday to Sunday night. There is no official party or something. This is just the banks of the Main River. People abuse the bank for their drinking orgies.
Yes, the homeless man allowed me to take pictures of his collected works. He collected all this in half an hour. I thought it was a good example of how many bottles are lying around by themselves. In Germany you get a deposit on some bottles.
But not on all trash.
His collection was only the top of the mountain of garbage you could collect there.
Holy cow. That's crazy!