Caldicot Castle (Welsh: Castell Cil-y-coed) is an extensive castle in the town of Caldicot, Monmouthshire, in South Wales. It was a possession of Thomas of Woodstock, a son of King Edward III of England.
In 1158 the manor of Caldicot passed to Humphrey de Bohun III, Earl of Hereford. He was responsible for building the stone keep and curtain walls of the present-day Castle. The de Bohun family held Caldicot for over two centuries. In 1376 the manor, along with 70 others, passed to Thomas Woodstock, third son of King Edward III, when he married Alianore de Bohun.
With the death of Edward III the throne passed to his grandson, the nine year old Richard II. As the new king's uncle, Thomas played an important role advising him. He was created Constable of England. He rarely visited Caldicot, his main estates being at Pleshey in Essex, close to the seat of power.
In 1381, however, Essex was convulsed by the Peasants' Revolt. This may be why Thomas decided to spend part of that year in Caldicot. During his stay he gave orders for major new work to be done on the castle. A new gatehouse and drawbridge were constructed. At the rear of the castle a dovecote was replaced by a new tower with private chambers, now known as the Woodstock tower. At the foot of the Woodstock tower two carved stones were to be placed, one marked 'Thomas' the other 'Alianore'.
As time passed relations between Thomas and King Richard grew increasingly strained. In 1391, on the orders of the King, Thomas was kidnapped and murdered. His property was confiscated and passed into the hands of the Crown.
The castle is reputed to be haunted by a number of ghosts and spirits including a grey lady, hooded monks and a mischievous poltergeist. At the centre of the activity is the Gatehouse Banqueting Hall; shadowy figures, as well as moving furniture, has been witnessed in this area. Many people have experienced unusual cold spots, as well as hearing footsteps in vacant parts of the castle.