The simplest but most beautiful of 'The Sisters' (a trio of great Provençal Cistercian abbeys including Silvacane and Notre-Dame de Sénanque), Thoronet, built between 1160 and 1190, is a masterpiece of sacred architecture. It’s remarkable for its ultra-austere style: pure proportions, perfectly dressed stone and the subtle fall of light and shadow on unadorned, but never severe, geometry. It's so well preserved that it's easy to imagine the strict lives the monks (and particularly the lay brothers) led. There's so much to see, but highlights include the graceful cloisters, the deliberately unadorned church, the chapter house, lavabo and cellars. Definitely fork out for the enlightening €3 audioguide. It's 14km from Lorgues, concealed in beech woods.