Lausanne doesn't merely have a ground floor. Perhaps because of all the hills, it has many bridges which go over the city itself. The result is that you can go upstairs and downstairs and find yourself on a different "floor" of the city.
Here's a little bridge just east of the train station: bridge over Rue Centrale.
And here are some views from the top of Pont Chauderon, perhaps my favorite spot in the city: