The immense Palais des Papes is the world’s largest Gothic palace and is a UNESCO world-heritage site. Built when Pope Clement V abandoned Rome in 1309 to settle in Avignon, it was the seat of papal power for 70-odd years. The immense scale, cavernous stone halls and vast courtyards testify to the popes' wealth; the 3m-thick walls, portcullises and watchtowers emphasise their insecurity.

Today, it takes imagination to picture the former luxury of these vast, bare rooms, but PDA-style audio-video guides introduced in 2012 show 2- and 3D imagery of the once sumptuous furnishings. Even without, you can see the splendour in the 14th-century chapel frescoes, painted by Matteo Giovannetti; in the intricate walls of the Pope’s bedroom; and in the superb Chambre du Cerf, alive with medieval hunting scenes.

Self-guided tours direct you from lower floors to crenellations; stop for coffee in the sky-high cafe. The guided two-hour Visite Palais Secret (Secret Palace Tour) takes you to secret towers, rooftop walkways and hidden chambers; reservations essential. The English-language version (€19.50) runs Fridays, spring and fall; the French-language version (€34.50) runs Saturday and Sunday, September to May and includes brunch.

Check the website for a complete list of opening hours throughout the year.