Cesar's Tower
On top of Aix-en-Provence, you can find an old and lonely tower erected in 1385. It's surrounded by typical mediterranean vegetation.
This place overlooks Aix-en-Provence city (you can see the TGV high-speed train line in the background) :
Again, you cannot park nearby. It's about 5 minutes walking. No engines, no noise. It's a very quiet place.
Then you can go for a walk as the vast area around is forbidden to cars !