Línea P
The Línea P (P line), officially the Pyrenees Defense Organisation (Organización Defensiva de los Pirineos), was a fortified line of defense built in the Pyrenees between 1944 and 1948 to prevent an invasion into Spanish territory. After the end of the Spanish Civil War, the government of General Franco decided to build a defensive line in the Pyrenees, that would go from the Mediterranean to the Cantabrian Sea, approximately 500 kilometres (310 mi) of fortified defensive points, stretching up to a depth of 60 km (37 miles) from the border.