Stairway to Heaven
... Or well not heaven exactly but the Seine in Paris at least.
I love that it's possible to stroll even closer to the river due to these stairs that'll lead you down to the border. I used to run along the Seine a couple of times and you can't really ask for a better jogging route than this. You can even do some sightseeing on your way, in the form of Notre Dame, Musée d'Orsay, Grand Palais, the Louvre, Pont des Arts and the Eiffel Tower, just to mention a few of the things you'll pass by on your way. You can't ask for a better way to do your exercise.