Archive of the Congregation for the Doctrine of the Faith

The Archive of the Congregation for the Doctrine of the Faith, based in the Vatican, (abbreviated to ACDF for Archivio Congregatio pro Doctrina Fidei), commonly referred to as the Archive of the Inquisition (or more fully the Archive of the Inquisition and Index), contains the Catholic Church's documents dealing with doctrinal and theological issues related to church teaching. It also contains information on political trials that were carried out when the papacy had temporal power over the Papal States.

More information on the Wikipedia page.