Garthmyl Hall was built in 1762, replacing an earlier timber-framed mansion of late 17th century date. In 1859 it was substantially remodelled involving the addition of stone quoins, new fenestration, pediment, and a Tuscan porch. The building is 2 storeys, brick with stone dressings and a slate roof. It has axial brick stacks with stone caps. The interior is Victorian.

Reference: Cadw listed buildings database.

RCAHMW, February 2011