also known for its karst , including the karst spring Fontaine de Vaucluse after which "Vauclusian Risings" are named. Important urban centres include Avignon , Orange , Carpentras , Cavaillon , and Apt . Demographics Urban population: 416,301 (83%) Rural population: 83,384 (17%)"" http://en.wikipedia.org/wiki/Vaucluse "You can run but you can't hide"