Just by luck, I happen on a CARNEVAL celebration weekend in Zurich. Yesterday, the old city center was alive with people, mardi gras-like beads, tons of confetti and an odd assortment of costumes, bands, and well lubricated people enjoying the event.
I did not arrive on site until about 7:00 p.m., but even at that hour the town was alive with action. Actually, I had arrived to find some place to eat dinner, but thoses plans were put on hold for a a bit so I could experience the festivities.
Walking just one block in either direction from the wild festival atmosphere brings you to the peaceful river and a great illuminating view church spires.