At the end of a carnival parade day
Yesterday (Sunday) was the day of the big carnival parade in downtown Wiesbaden. I wasn't able to go, just got there when people started to clean up and move everything to Mainz the neighbour city where there'll be the second biggest carnival parade within Germany today (biggest one is in Cologne).
The place behind the little carousel is called "Louisenplatz". I'll write more about it after the carnival season is over, promise.