Many who love Provence are familiar with Chateau La Coste, which produces some of the region's best-known rosé. But what many do not know (yet) is that since the vineyard was taken over by an Irish businessman, in 2002, not only have the wines gone organic, the sprawling domain has become the most ambitious art and architecture complex in France—and perhaps in all of Europe. The idea: to bring together art, wine and architecture in a way that is organic and site-specific, yet defies easy definition. Too vast to be a sculpture garden and too diverse to be an art collection, this exceptional compilation opened without fanfare in June.

Once inside the gate, the visitor is greeted by a sprawling glass and concrete restaurant/bookshop/visitors' pavillion surrounded by an eternity pool designed by architect Tadao Ando, guarded by a Louise Bourgeois crouching spider and monumental works by Alexander Calder and Hiroshi Sugimoto. The wine cellars are the work of Jean Nouvel; reconstructed Jean Prouvé houses are set to become a bookshop and wine kiosks; further along is a deconstructed music pavillion signed by Frank Gehry. Meander up the paths toward the hilltop chapel, whose outer casing is also by Ando, you'll find folded into the landscape works by a who's who of contemporary art, including Richard Serra, Jean Michel Othoniel, Michael Stipe, Tom Shannon and Sean Scully, among others.

Indoor galleries and other installations by Renzo Piano, Oscar Niemeyer and Ai Weiwei are in the works but part of the plan, organizers note, is that the site is designed never to be truly "finished". Fortunately, come next year art lovers will be able to sleep among these giants if they so choose: the owner has broken ground for a luxury boutique hotel, with construction expected to be completed next year. In the meantime there's a lot of ground to cover here—to see it all would take at least an hour and a half—and it's hilly, so wear good walking shoes. Admission 18 euros. Open year round.

Tina Isaac is Travel + Leisure's Paris correspondent.