If you want to, you can really easily spend a day just wandering around the old parts of the city - the streets and houses are so beautiful!
Info http://www.marvellous-provence.com/aix-en-provence/what-to-see/old-town
Address 48 Place Richelme, Aix-en-Provence 13100, France
Coordinates 43°31'45.036" N 5°26'53.643" E