Walking the GR11 (La Senda) trek, as described in this guidebook, takes you through Spain's Pyrenees from the Atlantic at Iruns to the Mediterranean at Calaques, and is one of the world's great trekking routes. The Spanish Pyrenees present a wonderland to the holidaymaker, whether backpacker, botanist, canoeist, cyclist, entomologist, ornithologist, mountain biker, skier, walker or simply anyone with a love of mountain scenery. In recent years the mountain organisations and authorities in the administrative districts of Guipuzxoa, Navarra, Aragon, Andorra and Cataluna have got together with local villagers to arrange the waymarking of a coast to coast (Atlantic to Mediterranean) long-distance footpath through the Pyrenees on the Spanish side. Designated the Gran Recorrido 11, it mirrors the French counterpart, the GR10. This has opened up miles of waymarked footpaths and tracks in an ever-changing environment, often in remote and high area, to numerous enthusiastic walkers of many nationalities but those seeking solitude will also not be disappointed. The GR11 is now a truly high quality, high-level mountain trail, a combination of spectacular high peaks, glistening tarns, deep green valleys and expanses of wild beauty as yet unseen by many visitors in addition to a moderate climate and easy access. This fourth edition includes revised maps, tables and profiles, accommodation details and route descriptions and will meet the needs of walkers on both day trips and longer expeditions.