The following links may be useful in planning your journey to Castelnaud or giving you ideas of things you can do whilst there:-
Ryanair have flights to many French provincial airports including Bergereac which is only about 60 minutes drive away from Castelnaud. Flights depart from London Stansted, Nottingham and Liverpool.
Jet2 also fly to Bergerac from Leeds/Bradford and Manchester to Brive.
It may be worth considering flying to other French regional airports if the timings are more convenient. A new service to Brive -la-Gaillarde from London City by Cityjet has recently started which may be convenient for anybody living in the South East of the UK and with Brive being only a short drive up the motorway from Souillac (see Travel) is a possible alternative to Bergerac
The following is a link to the SNCF (French Railways) website that gives times of trains to Sarlat and Souillac if you decide to hire a car locally. SNCF
There are a number of car hire companies at the airport, namely Alamo, Buggs, Europcar, Hertz and Avis. However you can usually get a good discount by booking a car through either Holiday Autos or Auto Europe
HOT AIR BALLOONING
If you would like to do something a bit special you can float over the Dordogne and all its castles and chateaux from a local site - in fact the balloons often float over Le Rouquet in the early morning or evening - a wonderful sight. Visit Montgolfiere-du-Perigord or Perigord-Dordogne-Montgolfieres for an idea of what you might experience
USEFUL LOCAL CONTACTS
Bike hire by the hour or day from BikeBus and they will deliver to Castelnaud!
More information of local attractions is also available from the local tourist office in Sarlat as well as from the many brochures in the apartments.