The overrated three
The Palais Grand-Ducal interior tours ($15, summer only) — 45 minutes of gilded rooms with rushed English commentary. Skip and just watch the guard change outside. The Chocolate House opposite the Palais — hot chocolate is fine but it's a hyped Instagram spot with $9 drinks and 20-minute waits. Try Namur or Oberweis instead. Rue de la Loge and the immediate old-town shopping — expensive tat, laminated menus, and coach-tour crowds.
Better uses of your time
Walk the Corniche path from Place de la Constitution down to Grund at sunset — free, and it's genuinely one of Europe's great city walks. Ride the free Pfaffenthal elevator both ways. Spend an afternoon at MUDAM ($8) which is properly world-class contemporary art in a Pei building. Take the free train to Wasserbillig for an afternoon by the Moselle. Any of these beats another lap of Place d’Armes.
Good to know
Is the guard-change worth it?+
Yes — it's small, dignified, free, and takes 10 minutes. Summer only (roughly mid-July to end of August). Don’t queue for interior tours after.
What about the city tourist bus?+
$22 for something you can do free on the tram and Pfaffenthal lift. Skip.