I’ve just finished putting together a guide to the GR11. The GR paths are a network of extensive paths that criss-cross Europe, mostly in France, Belgium, the Netherlands and Spain. Here in the Spain, GR stands for ‘Gran Recorrido‘ and here in the Spanish Pyrenees, we have a number of these GR paths linking key settlements, passes and valleys, but perhaps the most challenging and impressive of these GR routes and the one that many of our hikes are based around is the GR11. The GR11 stretches the entire length of the Spanish Pyrenees, from Hondarribia, on the Atlantic coast to Cap de Creus, on the Mediterranean coast, and covers a total of 840km, which is divided into 46 day long sections.
The guide can be found here: Hiking the GR11: A Practical Guide