I've been to Avignon. It's small enough to be mostly walkable, iirc.
Yes, there's Palais des Papes - at one point due to a schism in the Catholic church, Avignon became the headquarters, where the popes were, because reasons. I can no longer remember, but it's interesting.
Nice wine, château neuf des Papes.
There's also an outdoor swimming pool, La Palmeraie, so even though it's not on the coast, you can still get a bit of that kind of holiday vibe by spending a morning/afternoon chilling by the pool on loungers and taking dips.
www.piscine-avignon.net
And if you time it well, you might be there for le bal des teinturiers.
A French colleague had mentioned the rue des teinturiers to me, suggested I check it out, and it was a random coincidence that their annual festival/outdoor event was taking place.
Rue des teinturiers is the old tanneries district, there were some nice little bars and restaurants, we had a great Maroccan meal. And then we followed the sound of some music wandered down some little back streets and found a stage and some live music, a makeshift trestle table bar, and had a great time.
Just did a quick Google search, more info here, le bal des teinturiers is some time in July, apparently, so check the dates and you might catch it.
Guide to the rue des Teinturiers, one of the prettiest, most historic spots in Avignon and also one of the most fashionable.
www.marvellous-provence.com