In the early 1960s an archive department was established at Idrija City Museum. Since the early 1970s this has functioned within the Slovene archive network as a unit of the Historical Archives Ljubljana. The most important Idrija unit records consist of documents from the period when Idrija was well known for its quicksilver mine. This archive is one of the oldest and most important Slovene historical documents on industry and includes a large collection of charts and maps. The unit also preserves several records from the field of administration, education, economy, banking and associations and some documents on jurisdiction. The documents up to 1914 are primarily in the German language and in gothic script, whereas between the two wars the official language was Italian. The unit keeps over 200 records, representing some 750 linear metres of documents, the oldest ones dating back to 1700. A reference library, a microfilm laboratory and copying machines are available for use by the public. The archive publishes articles in the City Museum publication Idrijski razgledi ('Idria Views'). In June 2002 creative co-operation with other cultural institutions resulted in the organisation of the 6th International Symposium on Cultural Heritage related to the Mining Industry, Geology and Metallurgy.