Historical Archive of the Archdiocese of Cologne

The archive collects records from the Cologne diocesan administration and other church organizations within the diocese, along with personal papers and special collections. Since the 1980s, archives of further Catholic institutions, associations, and organizations have also been included. Its holdings include the archive of the German Bishops' Conference, comprising 410 shelf meters from 1925 to 1990. The first architect's papers arrived in 1984 with the estate of Alfons Leitl, followed later by those of Rudolf Schwarz and Fritz Schaller, among others.

The archive sits within a building complex designed by Hans Schumacher and Willy Weyres, which also includes the archbishop's residence, the seminary, and the seminary church of St. Petrus Canisius. The archive building has three stories, an angular floor plan, a brick facade, and gabled roofs, closing off to the west with the eight-story "book tower." Between 2005 and 2007, a three-story underground extension was built, invisible from outside, adding 2,200 square meters of space. Since 2015, a wall relief by Monika Bartholomé has complemented the curved 1950s staircase — its slender rods reflecting, among other things, how an archive reduces documents to what is worth preserving.