Are there nice beaches here? I've done some googling but can't seem to find much, we will do some sightseeing and a day trip to Arles but was also hoping there would be nice beaches we could spend a couple of days relaxing at? We are doing quite but of travelling so hoping there are some good ones nearby
There are many sandy beaches around Le Grau du Roi - La Grande Motte - Palavas. Not very close to Avignon which is in the hinterland, of course!
Avignon is not on the coast, or even particularly near it. If you look at a map (and you should if traveling in France), you'll see that it will take you at least an hour and a half to get to beaches in the Camargue (and that's without traffic or stops), 2 hours or more to get to beaches on the Côte d'Azur. And you'll need to tell us what a "nice beach" is for you. A good number of beaches in southern France are pebbles, not sand. If you're picky, that narrows down your choices.

You could find lake or riverside beaches not too far. http://www.avignon-et-provence.com/swimming-places-provence/, http://www.provenceguide.co.uk/swimming/offer-6-1.html
It's a long way down to the sea...

You can sit along the Rhone "behind" the Palais des Papes. Not a beach by any stretch of the imagination. I recall that there was an RV campground there.
And you could dance under the bridge (it is supposed to be under, and not on the bridge, as I remember). Didn't try to do either when we were there.

Dancing under the bridge (or half of the bridge) will be wet! And there is a 'nice' beach in Avignon on the island Barthelasse.
http://www.avignon-et-provence.com/avignon-tourism/pont-avignon/pont-avignon.htm#.VwZBp2f5OGM
I have a strange brain that remembers inconsequential things and spouts them out sometimes at inappropriate
times...I know the big stone bridge could have been danced on...
