Ampertain House

Ampertain House (also Ampertaine) stands on the edge of Upperlands, County Londonderry, Northern Ireland, a linen village of the Clark family, who operated mills on the Clady since 1736. The townland name is a corrupted form of Irish Áth an Phoirt Leathain, "ford at the broad bank".

Alexander Clark (1785–1871) built the current late Georgian house after 1821 (often dated around 1835). It has two stories over a high basement, five bays, a flat porch and a door with a fanlight in a round-arched niche, and eaves on a console cornice. In 1915, a two-story, three-bay, recessed wing was added. A round Victorian greenhouse once stood on a high plinth; a terrace is now in its place. A modest park with a windbreak surrounds the house; late Victorian gardens with ponds and rockeries were rediscovered in the 1990s. A lodge from around 1870 replaced two older gatehouses.

The house is Grade B1 listed and borders the Clark mill complex (William Clark & Sons). It was the most distinguished of several Clark residences; rows of workers' houses like Boyne Row and four mill ponds characterize the place. After a sale offer, it remains a private residence with around ten acres.