Les Baux, near St Remy and Glanum, has a history going back more than 6000 years. It is an ancient hilltop fortification which has now become a very popular attraction. The old fortifications and churches have largely been overtaken by tourist demands but the old ramparts provide spectacular views over the countryside below, from the history within. Well worth a visit if you can avoid the summer weekend crowds.
In 2013 this is "Monet, Renoir… Chagall. Voyages en Méditerranée". 
Visiting the village (free) and the castle (not free); hiking in the area.
Olive oil and wine produced in the valley are excellent.