From June 1944 until the last week of March 1945, the former Prussian State Library at Berlin sent for safekeeping, some 1.5 million books, as well as a large collection of maps and manuscripts, to an unworked salt mine in Hesse, with shafts at Heimboldshausen and Ransbach. The mine is about fifteen miles west of the Merkers mine, ten miles west of Vacha, and five miles west of the potash mine at Philippstahl. In August 1944 the University of Marburg Library sent some 250,000 books 80 miles to the northeast to the mine. Later that summer the Berlin State Opera and Theatre sent approximately 50 boxes of musical scores and sheet music for the musicians and actors and upwards of 200,000 stage costumes to the mine. In the spring of 1945 the Landes und Stadtbibliothek of Dusseldorf sent 500,000 books and manuscripts to the mine. Books were also stored in the mine by other libraries and private collectors. And German military archives relating to economics were placed in the mine at the end of March.