The delights of SO/ Paris, a new boutique hotel in a quiet and somewhat obscure corner of the Marais, begin with the cookie made of nuts, cranberries, and white chocolate that is waiting in every guest room.

Located on the banks of the Seine, the hotel is both in the middle of nowhere and the center of everything: a quick crossing to the Rive Gauche, 30 seconds from Île Saint-Louis, and in the other direction, the animated Bastille neighborhood.