4th arrondissement

Walk, walk and walk! This arrondissement is compact enough to be explored on foot and that's probably just what you'll want to do anyway. Otherwise, the metro may be not be too useful for covering short distances, but you may still want to use the bus line 76 for the Châtelet-Bastille itinerary or line 67 for Châtelet - Île St. Louis, especially if you have a card for multiple trips or a carte orange.

The RATP network has bicycles vélos for rent next to the Bastille station: