Drum Castle is a castle near Drumoak in Aberdeenshire, Scotland. For centuries it was the seat of the chief of Clan Irvine. The place-name Drum is derived from Gaelic druim, 'ridge'. The original 13th-century tower of Drum Castle has been suggested as the work of medieval architect Richard Cementarius, who built the Bridge of Don in Old Aberdeen. It is believed to be one of the three oldest tower houses in Scotland (and notably unaltered). A large wing was added in 1619 by the 9th laird, and further alterations were made during the Victorian era.