From his birth, Man was acutely aware of the Sacred, which appeared, in the most primitive religions, in the observation of rituals including displacement towards necropoles, which were at the same time cult monuments. This human feeling of belonging to a world whose components exceeded comprehension involved the birth of prayer, prayer to obtain grace, prayer of contrition, prayer to meet this power that, above men, holds them in his hand. These places could be springs or rivers where one comes to purify and regenerate oneself, mountain tops where one meets the sky, sacred stones and trees that one believed to have life, places marked by the presence of a saint character.

For some believers, prayer gains in intensity if done in a place more remote from one's residence, after a voyage in which they were foreigners, far from their usual landmarks. But this is valid for a minority only. The majority of pilgrimages happens close to residence, in a range of maxiumum a few days' walk. In the Middle Ages many arose from the possession of relics whose trade was flourishing and which enabled many negociations from one end of Europe to the other.

Within each group, but only within this group and never elsewhere, brotherhoods are concerned about peace, morality and mutual assistance, which does not prevent them from often taking part in the most insane festivals during Carnivals. From the sixteenth century trade brotherhoods multiply; they regulate the exercise of such or such profession. The selected saint sometimes has a relationship with this trade: saint James, patron of travellers, is sometimes the protector of merchants, inn-keepers, hat makers. Protector of harvests, gardeners put themselves under his stick both in Germany and in Switzerland or France.

Throughout all Europe, the increasingly numerous travellers generated a hospitality network more particularly intended for them, in total symbiosis with the road which, for pilgrims, is a kind of prolongation of each sacred place. There appeared for them, merchants or pilgrims on the way to a multitude of sanctuaries, a strange tripartite architecture perfectly adapted in its most complete form.

The chapel offers a shelter and a bench to the passer-by and counters often allow the distribution of food. No modern lodging is this functional. Some vestiges of these buildings condemned in mass by the widening of roads still remain, all the more invaluable as they are rare, disfigured and, even today, ignored and thus threatened: Pons, Pradelles or Cadéac in France, Piperno in Italy, Puente-la-Reina or Castrogeriz in Spain, the cathedral of Lausanne in Switzerland.

A splendid example of what such a refuge in a particularly hostile environment represents for man is still offered on the old way from Bayonne to Burgos, in Cegama, in Guipuscoa. Almost on the top of the mountain a cliff closes the horizon and seems to prohibit any passage. Some steps away, it is miraculously opened by a stone tunnel (is it completely natural?), Saint-Adrien tunnel. Below and opposite, one finds the door of a tiny chapel and the equally small one of an inn. This formidable and protective cave, this beneficial giant is often described by travellers, and all pilgrim songs speak about it.