Galeries Lafayette are worth a visit even if you aren't going to buy anything. Just the very stained-glass dome makes it worthwhile to enter the building at least once. This magnificent structure represents the Belle Epoque and Art Nouveau. The seventh floor hosts weekly 30-minute fashion shows. On condition that you book a place in advance, you will be the first to see the creation of world's leading fashion houses. Finally, rooftop terraces showcase gorgeous panoramas of Paris. However, it is a seasonal delight: visitors are allowed on the top floor only during summer months, so don't miss your chance.