The Galeries Lafayette in Paris is probably the most beautiful store I've ever visited. Next door to the Palais Garnier, it is worthy of stop on even the briefest trip. It is a high-end department store in the 9th Arrondissment, but its most valuable offerings are free.
The number one reason to go is the jaw-dropping stained glass art nouveau dome, original to the 1912 design.
|40, Boulevard Haussmann, 75009 Paris, France|
The second reason to go is the breathtaking view of Paris on the top, seventh floor. Across is a close-up view of the Palais Garnier and in the distance is a familiar landmark. The vast terrace is carpeted with green astroturf and has benches for your enjoyment. Again - all free.
The number 3 reason is of course the shopping. Every luxury brand you can think of is here. In fact, I found a discontinued perfume to my delighted astonishment.
The Galeries also has various good and inexpensive eateries on the sixth floor to satisfy the most famished shopper/sightseer.