Whilst essentially an early nineteenth century building , the Old Nag's Head incorporates in its structure the remains of a tower of the eastern or Dixton Gate of the town. The medieval work is probably fifteenth century and how much fabric from this date may survive in the present building is unknown. The Dixton Gate was otherwise demolished probably in the eighteenth century and was replaced by the turnpike gate further down the street.
The medieval fabric of the building is red sandstone rubble, whilst the nineteenth century fabric is probably also red sandstone but may be brick, particularly in the upper storey. The tower remains unpainted, the inn is rendered and painted and the south-east wing of the inn, formerly the stable, is painted rubble. The building has Welsh slate roofs with red brick stacks. There is a main rectangular block with the half round tower on the north gable and the east wing projecting from the south-east corner. It is two storeys with an understorey and the tower has a battered base. The entry to the main block is in the gable end and has a recessed door on the left with a flat hood on brackets. There are two windows on each floor, which are all four over four pane sashes except at the top left which is a six over six.
It is Included in a higher grade for its interest as an early C19 public house which retains its character as well as a significant portion of a medieval gate-tower.
Source:- Cadw listed buildings, NJR 25/05/2010