The Haute Ville — the upper town — is the historic heart of Luxembourg City and where most of the sights cluster. It occupies the sandstone plateau between the Pétrusse and Alzette valleys, defended on three sides by sheer cliffs that gave the medieval fortress its strength. The streets are compact, the buildings mostly 18th- and 19th-century with older Renaissance fragments in the lanes around Place Guillaume.
The main pedestrian thoroughfare runs from Place d'Armes (cafés and the Cercle Municipal) past the cathedral to Place de la Constitution and the Gëlle Fra. South-eastwards, the Chemin de la Corniche follows the ramparts above the Grund. North-east, the streets climb to the Marché-aux-Poissons, the Grand Ducal Palace, and the Bock. This is where you spend most of a first visit.