After visiting Palais des Papes - take a walk up the hill (it is a haul)
The view is breathtaking. There is a lot of greenery - there are benches - if you don't have your own bottle of water, there is a snack shack (that I am sure is crazy expensive, but it is there if necessary)
You can see the "Pont d'Avignon" (St Benezay bridge) and get more of a feeling for the city with the bird's eye view.
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