The Salamanca Papers (Catalan: Papers de Salamanca) refer to the 300,000 documents and 1,000 photographs confiscated from the Catalan government after the Spanish Civil War and transported in 12 railway freight wagons to the city of Salamanca to be stored in what was later to become Spain's Civil War Archive (Archivo General de la Guerra Civil Española). More informaiton on the Wikipedia page [1]