Go to the Montparnasse train station. Board the TGV, the fast French train that will take you from Paris to Saint Jean de Luz in southwest France in five and a half hours. Walk to your centrally located hotel to check in and leave your bags. Stroll the Rue Gambetta, the pedestrian-only street that is the commercial hub of the city. Watch the sun set over the Atlantic Ocean.
Drive east toward Ascain, a small Basque town about 15 minutes from Saint Jean de Luz and follow signs to the "Petite Train de La Rhune." Leave your car in the parking, buy tickets and take the train to the top of La Rhune. Look for the Basque ponies called pottoks on the way. From the top, you will be able to see Biarritz and Bayonne to the north, San Sebastian. Buy lunch at the Spanish venta and take the train down. Alternatively, bring good hiking shoes and walk one direction.
Explore Bayonne, the center of government of the French department of Aquitaine. Visit its cathedral, walk through old town, eat in a cafe overlooking the River Nive. Take time to see the Basque Museum which gives you an idea of the history and culture of the Basque people, as well as the traditional dress and music.
Drive inland about 30 minutes to the Basque village of Sare, designated one of the most beautiful villages of France. Visit Ortillopitz, a restored Basque farmhouse. Visit the prehistoric caves of Sare called Grottes de Sare. Tour the small downtown square with its ancient church. Have a drink at the outdoor tables of the local cafe and buy a gateau Basque--a traditional basque cake--from one of the boulangeries.
Drive south into Spain on the A10, the major toll road in the area. Take the central San Sebastian exit and park by the beach. Walk La Concha, one of the most beautiful beaches in Basque Country. Visit old town for tapas--plates of finger foods available in most bars. Walk up to the bar to look over the different platters and point to the ones you want to try. The aquarium at the north end of La Concha is the best in the area.
Choose activities depending upon the season. Hike in the Pyrenees using Sare, Ascain or Espelette as a starting point. Lounge on a beach if the weather is good. Hike the forests for mushrooms in the fall. Visit local festivals, open air markets in Saint Jean de Luz on Tuesday and Friday mornings, and practice your French.