Bock Casemates Official Tickets Underground tunnels—UNESCO (€8).
Grand Ducal Palace Official Guided Tours Royal residence—summer only (€15 timed).
Notre-Dame Cathedral Free Gothic—stained glass, crypt (free).
Mudam Contemporary Art Museum Official Pei architecture—exhibits (€8).
Vianden Castle Day Trip Official Medieval fairy-tale castle (€10).
Adolphe Bridge Free Iconic stone arch (free).
Pétrusse Valley & Casemates Free Green gorge—views (free).
National Museum of History and Art Official Roman mosaics, contemporary (€7).
Fort Thüngen & Three Acorns Official Fortress museum—Dräi Eechelen (€5).
Place Guillaume II Free Central square—markets (free).
Gëlle Fra (Golden Lady) Memorial Free WWI monument—views (free).
Philharmonie Luxembourg Official Tours Concert hall—architecture (€10).
Luxembourg City History Museum Official Interactive city story (€5).
Villa Vauban Art Museum Official 18th-19th century paintings (€5).
Grund Quarter Free Lower town—river, abbeys (free).
Pfaffenthal Lift Free Panoramic elevator—valley views (free).
Am Tunnel Gallery Free Underground art—bank tunnel (free).
Natural History Museum Official Dinosaurs, geology (€5).
Chemin de la Corniche Free "Europe's most beautiful balcony"—views (free).
Clausen & Neumünster Abbey Free Cultural centre—events (free).