The mountains that limit France and Andorra to Spain were a natural crossing for those seeking freedom and fleeing persecution and war. Despite of contiguity between these countries, crossing the border was a risky action even lethal in some cases.
The difficulty of the road, especially in some parts of the mountains, the cold and snow, the actions of some unscrupulous guides and the possibility of being arrested and repatriated by the police guarding the border were some of the problems that foreigners had to face on their way to Spain seeking freedom and often this experience turned into a real ordeal.
Crossing the Pyrenees was done with the help of guides, known in France as passeurs. Spanish guides were mostly people born in the mountains that were trained and they knew about the roads, medium and people. Many of them had done the same tasks during Civil War in the opposite direction. They had accompanied those who had sought refuge in France through the Pyrenees. Others had been previously engaged in smuggling.
For older people and many poorly trained and prepared, the hardness of walking across the Pyrenees made necessary to guides having a set of trustable farms where to rest before resuming the road. Spanish security forces thoroughly watched these farms, whose inhabitants were living in constant danger.
The occasional passeurs should also be mentioned. They were neighbours from villages near the border that, beyond network or organization and to the despair of some cases, volunteered to accompany the escapees to the closest pass between mountains.
The motivations that led them to do this work were several: first the political and personal commitment that had an important influence, and on the other, the substantial economic gains that this action entailed.
Support structures, so-called evasion networks, were organized to help people who wanted to escape from occupied countries. Initially, these were responsible for the arrival in Vichy France but soon expanded to help the escapees to cross the Pyrenees to enter Spain. The Allied Secret Services played a key role in the organization of these networks. British and Americans drove most evasion networks. In addition to moving people, they could take care of documentation addressed to the Allied army organized in North Africa or England and to the various exiled governments organized in London. On the other hand, expeditions back from Spain allowed to carry reports and money intended for organizing resistance.
There were many evasion networks; each specializing in a particular territory and the evacuation of certain groups, and each with several branches depending on the scheduled itineraries.
Barcelona was the most common destination for refugees, where from his subsequent escape through Spain and Portugal was organized till reaching a port, mainly Gibraltar and Lisbon were chosen, from which shipping to a safer destination.