The Avignon Popes' private quarters in the Palais des Papes have long been closed to the public. But now you can take a tour which gives a fascinating insight into the pontiffs' secret daily lives.
Click here to book a hotel in Avignon
The tour - sometimes called Les Coulisses du Palais (Behind the Scenes at the Palais) - lasts around two hours. It's offered in English for a very limited period in spring and autumn. If you speak French, you might consider one of these tours, which are available throughout the year.
The public tour goes through the Palais Vieux, a forbidding fortress commissioned in 1334 by the austere Pope Benedict XII.
It will take you to vast official spaces such as the Consistory Hall, where the cardinals gathered to deliberate on ecclesiastical matters, or the Grand Tinel, an enormous, vaulted banqueting room. This is the official face of the Avignon Papacy. Click here to read more about the history of the Palais des Papes and its public areas.
The Secret Tour is very different in character from the public one. It's focussed on the Palais Neuf , which was largely developed by Clement VI (pictured top left), a Benedictine monk from a wealthy noble family. Clement loved art and luxury and fully intended to enjoy his papacy. "My predecessors did not know how to be pope," he reportedly said.
Click on the map of the Palais des Papes to enlarge the image and to get a sense of how the old and new parts relate to each other.
Intriguingly, the tour weaves in and out of the public areas and the contrast is striking. The peaceful atmosphere behind the scenes takes you away from the tourist crush, and gives an intimate sense of the contemplative life the clerics lived there.
It also makes you realise just how much the main part of the Palais des Papes has been restored - and how much, despite its status as a UNESCO World Heritage site, is still left to do.
After the French Revolution, when the building was vandalised and pillaged, it was used as a barracks and prison.
The soldiers showed scant respect for this bastion of ancien régime power, whitewashing over frescos (then covering the walls with their own graffiti) and building mezzanines to cram more men into the dormitories.
There are no fancy explanatory panels and displays in this part of the Palais Neuf, and you need a little imagination to picture the glory that once must have been.
The Secret Tour starts behind the Palais in the garden, orchard, vineyard and kitchen garden, which also housed a little zoo to accommodate animals, including lions, bears and parrots, offered as gifts to the Pope.
The dressing and wardrobe rooms when the vestments were kept are richly decorated with geometric patterns, coats of arms and animals (pictured).
The bathroom suite is a spacious affair with three interconnecting chambers including a steam room; the study boasts frescos of hunting and fishing scenes.
The Popes kept nightingales and other songbirds in the bedroom in golden cages. Did any of them have mistresses (the popular Clement VI, in particular, was described as "no saint" by one historian)?
"We don't talk about that," the guide twinkles. "There's nothing about it in the official documentation."
One thing is well-documented: all the Popes were fond of wine. Click here to read about wine and the Avignon Popes.
You also see the Pope's private treasury chambers, library (which once contained two thousand books), reception room (pictured above) and a simple, beautiful chapel dedicated to Saint Michael.
Then you climb up on to the roof of the Saint Laurent Tower to discover sweeping views of the turrets and roofs of the Palais and city as well as, in the distance, the Fort Saint-André in Villeneuve lès Avignon across the Rhône river.
The "official" visit of the Palais des Papes is not recommended for anyone of restricted mobility, and that applies even more to the Secret Tour.
The steep, narrow spiral staircases and crumbing steps give you the sense of navigating a building site, though this also lends the tour an exciting, exploratory quality.
Be sure to wear comfortable shoes and, in summer, come armed with water as, obviously, there are no drinks vending machines or cafeteria in this part of the Palais.
Because of the inaccessibility of some of the areas, a maximum of 18 visitors can be accommodated: you can book the Secret Palace tour online here (scroll down to the bottom of the page).