The historical heart of Sousse is listed as UNESCO World Heritage. It is worth exploring beyond the main sights - you will be rewarded by its atmosphere.
Wikipedia http://en.wikipedia.org/wiki/Sousse#Sights
UNESCO Website http://whc.unesco.org/en/list/498
Address (Unnamed Road), Sousse, Tunisia
Coordinates 35°49'32.12" N 10°38'16.548" E