Ardeche is one of the quietest areas in France (no rail or Autoroute), yet it is still easy to access by either air, TGV, or by road.  See the map below, or use the following link for driving directions to St Laurent sous Coiron from any where in Europe:

 http://mqdirect.mapquest.fr/map.adp?venue=al1wa%261.

You will need a car:  there are international rental agencies at Valence TGV, including Alamo, Avis, Budget, National, Europcar, Hertz, and local agencies such as Carrier.  Make certain you reserve BEFORE you arrive - rental rates are much better when you reserve from outside of France.

There are two good options when flying into France:  fly to Paris (Charles de Gaulle airport, or CDG), then take the two hour ride on the TGV directly from the Airport; or fly to any of the regional airports indicated below.  For those with easy access to Stansted airport, Ryanair flies to St Etienne, less than 80km from the mas.  The drive from airports at Lyon and St. Etienne is about two hours;  St. Etienne is closer, but due to 'scenic nature' of roads...it takes the same amount of time!

St Etienne - 80 Km (Ryanair)

Lyon - 150 km

Nîmes - 135 km

Montpellier - 180 km

Grenoble - 180 km

Montelimar - 30 km

Valence - 60 km