Avignon was the seat of the papacy for most of the 14th century, and the Palais des Papes still towers over the city as proof. It is one of the largest Gothic buildings in Europe, and standing in its vast empty halls gives you a sense of just how much power and wealth the popes concentrated here.
The medieval walls survive almost intact, encircling a compact old town of narrow streets, small squares, and stone facades. The famous Pont d'Avignon — four surviving arches of a medieval bridge — juts into the Rhone just below the palace. Every French schoolchild knows the song.
Avignon is also a living city, not just a museum. The Festival d'Avignon in July transforms it into one of Europe's great theatre events, with performances spilling out of the Palais and into courtyards, churches, and streets across town. The rest of the year it serves as a natural base for exploring Provence, with excellent restaurants, a lively market, and good rail connections in every direction.