The cities of Toulouse, Carcassonne and the principality of Andorra form a triangle in which Ariège nestles. From those three places the beauty of the Ariège Pyrenees is easily reached.
GPS Warning: If your final destination is a small mountain village, don't place complete trust in your automatic navigation system which might direct you over a mountain pass closed by snow or over small winding roads when a road that goes around the mountain would be faster. If your hosts have given you specific directions for arriving at their place, follow them.
Barcelona is a popular weekend break destination for Ariège inhabitants because it’s just 4 hours by car from Foix. You can also take an inexpensive Spanish commuter train from the border town of La Tour de Carol in the department of the Pyrenees orientales. A train from Toulouse ends there, stopping at Foix, Tarascon, Ax-les-Thermes, Mérens and other villages. You get out and cross the tracks to get the Spanish train (the track gauge is different). Then you buy a ticket on the train from the conductor.
It’s hard to find information on this train, which offers a very scenic journey through the Pyrenees. The name of the town in Spanish is La Tor de Querol but the main Spanish railway site, renfe.com, doesn’t list it as a destination or point of departure when you do a search. It’s actually part of the Rodalies de Catalunya commuter train network, route R3. Use this link to get the timetable: http://www.renfe.com/EN/viajeros/cercanias/barcelona/
The synchronisation of the French and Spanish connections at La Tour de Carol is poor, so study the timetables carefully (use voyages-sncf.com to find the timetable on the French side). You can also park your car at the station and just take the Spanish train.