Lyon's historic old town on the banks of the Saône is fairly typical of many "old town" areas in France - narrow winding cobblestone streets with eclectic restaurants and shops.
However, unlike many other old towns, Lyon possesses traboules - passageways between streets and courtyards. The traboules were used in the 4th Century to transport silk from the river to the town. Many of the traboules are now closed to the public, but there are still a substantial number that can be accessed - although they are often extremely hard to find, usually hidden behind doors to apartments. However, an entertaining afternoon can be spent discovering the traboules of Lyon.
Lyon's old town is dominated by the Basilique de Fourvière on the hill above the old town. The basilica was completed in 1844 and is fairly typical of the design of that time. It's a steep climb from the old town (although there is also a fernicular) but the reward is a beautiful view over Lyon.
The other thing that Lyon is known for is it's food - especially offal. I can certainly recommend the local blood sausage, the "Veal head" - not so much.
The food in Lyon was delicious, albeit very heavy even for French food, but of course easy to eat if you wash it down with a "pot de Lyon" (carafe) of Lyonnaise wine :)