The "little yellow train" has service from Bourg-Madame and from La Tour de Querol, both easy hikes into France from Puigcerdà. The border at La Tour, a pretty one-hour hike, is marked only by a stone painted with the Spanish and French flags. It can also be picked up in Villefranche. The carrilet (narrow-gauge railway) is the last in the Pyrenees and is used for tours as well as transportation; it winds through the Cerdanya to the walled town of Villefranche de Conflent. The 63-km (39-mile) tour can take most of the day, especially if you stop to browse in Mont Louis or Villefranche. Be aware that in low season the trains are infrequent. Timetables are available at the stations or on the website.
Puigcerdà, 66760, France