The Pyrenees form the natural border between Spain and france. The mountain range extends from one sea to the other, from the Atlantic to the Mediterranean, always a good excuse for hikers to symbolically cross over and stay away from home two months.
Of course there is a fan group of the Pyrenees versus one of the Alps. The Pyrenees are very different from the Alps alltogether. There are no large lakes, but many high situated small ones. There are almost no passings over the Pyrenees from France into Spain. The famous exceptions - St Jean-Pied-de-Port and Col de Somport - are used by the Way of St. James, Camino de Santiago.
There are plenty of good hikes, among them the GR10, the Haute Randonnée Pyrénéenne, and - on the Spanish side, the GR11.