A walled garden survives to the south. The place appears on the 1842 Ordnance Survey six-inch map under a curious double identity: both 'Lunatic Asylum' and 'Cittadella', the latter an Italian word for a small fortified city or citadel. Locally, it went by neither of those names. People called it Bull's Asylum, a nickname whose origins are not recorded but which carries its own particular atmosphere.

The establishment was founded in 1799 by William Saunders Halloran, who opened his private asylum at Knockrea, near Cork, at a time when the treatment of mental illness was beginning, slowly and unevenly, to shift away from the purely custodial towards something with at least the appearance of medical seriousness. Halloran's Cittadella housed approximately 26 people, a relatively small number that may reflect the private, fee-paying nature of the institution rather than any shortage of need. It continued to operate until 1870. The three-storey residential house at the eastern end of the complex, nearly square in plan and carrying the name Cittadella, still stands; its entrance front of four bays features an off-centre round-headed door with a plaster surround and plate glass sash windows. A later two-storey range attached to the north has since been converted into private houses, so the site is now a layered thing, part ruin, part residence, the asylum and the domestic quietly coexisting.