Located on the O'Grady, Viscount Guillamore estate, Fort Grady was valued at £14 in the mid 19th century and occupied by John O'Connell. In 1837 Lewis describes it as a farm house formerly the residence of the father of Viscount Guillamore. In 1814 it was occupied by Mr Daniel McAuliffe. In 1786 Wilson refers to it as "Knockbrack, the seat of Mr. Gredy". A house and farm are still extant at the site.