I doesn't cost anything to visit the Pont du Gard. Go over the bridge at Remoulins, turn right up the lane with the river on your right, this will take you to the PdG bypassing the visitors centre.
Maybe you can still pass over it by car/bike as you would a normal bridge, but as soon as you stop it costs money. I was there when it had yet to be turned into a revenue generating honey pot which no one has picked up on and which was over 20 years ago when I worked in Avignon for a year and a bit. We used to go to the Pont Du Guard for lunch. It was very quiet and agreeable back then totally unspoiled or sullied by mass tourism. You were free to roam. I did revisit in 1999 I think but it had by then already been ruined.
Still a magnificent aquaduct built by the Romans to carry water from Uzes to Nime. As I say water flowed on the top which was covered by huge slabs of rock with occasional breaks so you could jump down and walk along inside. Sadly you no longer can. I guess a few people jumped killing themselves so spoilt it for the rest of us. It was pretty windy on top especially if the Mistral was blowing.
The Palais de Papes is worth visiting in Avignon and there are some lovely bars in the old town.
Orange to the north has a half decent amphitheatre and as does Nime to the south which is still used for bull fighting or it was. Then there is the beauty of the Carmargue wet lands to the south.
