As car traffic has been gradually cut back, the banks of the Seine are slowly reverting to towpaths where nothing can bring down your good mood. These magnificent corridors of peace and beauty are where you come to stay in shape, with or without a running coach. Run down the Seine's Left Bank from the Port Solferino - under the eponymous bridge - to Port du Gros Caillou, and just level with the Musée Branly, take advantage of its climbing wall for 3-10 year olds and a 100-m running track. There is also a 2-3-km fitness trail equipped with gym apparatus, where from early July to late October, you can take free boxing, rope-skipping, Pilates, skateboarding, and rugby classes by booking online. It goes without saying that the magical setting of this urban landscape, which has been a UNESCO World Heritage Site since 1991 and is so beloved of Parisians, also lends itself beautifully to a romantic stroll.