In reply to TommityP:
I've been to Laragne many times on paragliding trips and regularly flew over Orpierre or climbed there in the evenings.
You can get the TGV to Aix en Provence, (or fly to Marseille, then get a bus to Aix) then there are local trains that take you to Laragne or Saleon which is close, certainly an inexpensive taxi ride.
The other end of that train line is in Grenoble, but if travelling from there you'd need to change in Veynes. It's a very pretty train ride through the mountains.
How you get to Grenoble, Aix, or Marseille is perhaps a choice of bus/train/plane from UK.
Here are some ideas:
http://www.flylaragne.com/