The Old Town focuses on two squares, the most important of which is place d'Armes , fringed with cafes and restaurants. To the north lie the city's principal shops, mainly along Grand Rue , while on the southern side a small alley cuts through to the larger place Guillaume , the venue of Luxembourg's main general market on Wednesday and Friday mornings and flanked by the bland buildings of the city authorities. A block away is the Ruritanian Palais Grand-Ducal , originally the town hall, but adopted by the Luxembourg royals as their residence in the nineteenth century.

Close by, a group of patrician mansions bordering the Marche aux Poissons has been converted into the city's largest and most diverting museum, the Musee National d'Histoire et d'Art , which holds an extensive collection of Gallo-Roman archeological finds; however, it's currently being renovated - check with the tourist office for details. East of the museum lies the Rocher du Bock , a strongpoint where, in 963, Count Siegfried built the fort that was to develop into the town. It was an ideal defensive position, and in 1648 the French developed the natural advantages of the site to turn Luxembourg City into one of the most strongly defended fortresses in Europe. The streets here cling to the edge of the plateau, overlooking the sharp drop below, at the bottom of which nestle the slate-roofed houses of Grund - accessible by lift from place St-Esprit. The most substantial and accessible fortifications are the Bock casemates (daily March-Oct 10am-5pm; ?1.70). Used as bomb shelters during World War II, their galleries honeycomb the long protrusion of the Bock. There's nothing much to see inside beyond a few rusty old cannons, but there are fine views over the city's spires and aqueducts. From the Rocher du Bock you can follow the dramatic chemin de la Corniche to place St-Esprit, where the top of the gigantic Citadelle du St-Esprit bastion, built in 1685 by Vauban, has been levelled off and is now a grassy park. There are more casemates close by, the Casemates de la Petrusse (Easter & July-Sept guided tours 11am-4pm; ?1.70), hollowed out by the Spanish in 1674 and accessible by way of some steps on place de la Constitution. The nearby Cathedrale Notre-Dame , whose slender black spire dominates the city's puckered skyline, dates from 1613, but it has been remodelled on several occasions, creating the architectural jumble that exists today: the transepts and choir are in a clumping Art Deco style, whereas the (much more appealing) seventeenth-century nave is Renaissance. Inside, items of interest are few and far between, but there is a plaque in the nave honouring those priests killed in World War II, and the Baroque gallery at the back of the nave is a likeable affair graced by alabaster angels and garlands of flowers. In the apse is the country's most venerated icon, The Comforter of the Afflicted , a medieval lime-wood effigy of the Madonna and child which is frequently dressed up in all manner of lavish gear with crowns and spectres, lace frills and gold brocade.