Halmyre House is a 19th century mansion which incorporates the remains of a probable 16th century castle.

The oldest part of the building contains two vaulted chambers from the basement of the old castle within the main block of the house which has external walls around 1.0m thick. The castle is originally thought to have measured around 18.3m NE to SW by around 7.2m NW to SE.

The earlier castle was a property of the Tweedies of Drumelzier until the early 17th century when the Halmyre estate was sold to John Murray.

The property was extensively remodelled in 1856 in the Scots baronial style. In 1867 the estate was inherited by the eccentric gun collector Charles Gordon following the death of his aunt and uncle with whom he had lived at Halmyre.