This is a fascinating place both historically and geographically. The pass was one of the main places of the exodus of the Spanish Republicans after the victory of the Franco troops in 1939 . Nearly 100,000 people have crossed this pass to take refuge in France and in Latin American countries and a memorial is close to the road. Historically there are also echos of WW2 with a Gestapo site located on the border. Geographically there are 2 border markers and a Spanish triangulation point as well as disused border control facilities from both countries. In addition to the road crossing there is also an international rail crossing through the Balitres railway tunnel which passes under the pass. Full report details with maps and photos is here