Hallforest Castle is a keep, one of the oldest in Scotland, as it dates from the 14th century. The castle is believed to have been built by Robert the Bruce as a hunting lodge; he is said to have granted it to Robert II Keith, Marischal of Scotland, the predecessor of the Earls of Kintore. Mary, Queen of Scots visited Hallforrest in 1562.
The castle was frequently attacked during the 17th-century wars. It may have been abandoned shortly afterward, although it remains the property of the Earls of Kintore.
Hallforrest is a plain oblong tower 15 m long and 11 m wide. It once had a parapet, and probably a stone roof resting on an upper arch. It had two vaults, divided by entresol floors. It seems that the entrance led to the first entresol floor. There are small gun-loops to the basement, which may have had a cattle door.
Originally the castle had six floors. There are windows on the south. There is no evidence of masonry stairs; ladders and hatches must have been used. The interior is now ruinous.
To the north there are traces of what may have been an enclosing wall, and to the north west traces of a possible ditch or moat.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.