Aosta carries more Roman masonry per square metre than almost any city north of Rome. The original grid of Augusta Praetoria is still legible in the street plan, and the major monuments — the Arch of Augustus, the Porta Praetoria, the theatre, and the walls — are still standing after two thousand years. Wandering between them takes a morning at a relaxed pace, with no admission fee for the outdoor sights.
The medieval layer is worth equal attention: the Collegiate church of Sant'Orso has a Romanesque cloister of real beauty, the Cathedral holds Roman mosaic floors beneath its neoclassical facade, and a clutch of Norman towers punctuate the town edges. Beyond the walls, the Saint-Martin-de-Corléans Megalithic Area adds a prehistoric chapter that predates the Romans by several thousand years. Outside the city, the Aosta Valley opens into one of Europe's great alpine landscapes — summer hiking and winter skiing in close reach.