Frederheim

Situated just off the Altdorf to Middenheim road, Frederheim is technically a possession of the Emperor, but he has given oversight of it in all but name to the Cult of Shallya, which maintains a walled hospice and sanatorium for the treatment of the insane there. Frederheim is itself a small village with no resources other than farming, and the villagers make ends meet by working for the Sisters.

Visiting the Great Hospice is difficult, for the Sisters are most concerned for the welfare of their patients: Outside disturbances are not good for unbalanced minds. The Sisters provide for all their own needs, either from their own resources or those of the villagers. They have no need to import anything from the outside, thus limiting potentially upsetting contacts. Rumours say, however, that this care for the insane covers up something darker—people held against their will for unknown reasons, even though they are perfectly sane. No one knows the truth of this, but few who hear the rumour would believe the Shallyans could ever be involved in such a thing.

Source

 * Warhammer Fantasy RPG 2nd ED -- Sigmar's Heirs (pg. 81-82).