The castle is built almost wholly of local rubble stone faced with squared blocks of local gritstone. The late C19 work used very closely matched stone with some red brick and pseudo timber framing in those additions to the Great Gatehouse which formed J R Cobb's own house. The house parts are roofed in red tiles while the towers are roofed in lead.
The plan of the castle is a rectangle-to-oval circuit of walls round the bailey with the Great Gatehouse in the centre of the south wall and the motte and its crowning keep in the north west corner. Thus, clockwise from the main entrance : Great Gatehouse : South West Tower : de Bohun Gateway : Keep : Woodstock Tower : South East Tower : Great Hall and Private Apartments, and back to the entrance.
The castle exteriors are described from the Great Gatehouse in this order, firstly the outer elevations and then the elevations to the bailey.
Outer elevations :
The Great Gatehouse is externally very largely of the late C19 to early C20 and is complete as rebuilt by J R Cobb. Central projecting section of two tall storeys over a battered base. Central entrance arch and oak drawbridge flanked by two lancets on either side. The first floor has three larger windows in projecting frames and two rows of small square lights. Battlemented parapet above. Three storey towers flank this section, each storey with one window as above; the towers rise to machicolated and castellated parapets all complete. The curtain is complete to the wallwalk, but without castellations.
The South West Tower is a drum with battered base. It is complete apart from some damage to the parapets. The curtain was undergoing repair at the time of inspection. It is largely complete to the wallwalk, but without castellations.
The de Bohun Gateway (or West Postern Tower) is complete to the parapet and has the unusual feature of an arched gateway to the outside. This is similar to one at Pembroke Castle. The curtain is complete to the wallwalk, which rises up the side of the motte, but without castellations.
The Keep is a large circular tower of three storeys with an attached D-shaped tower on the outside which contains garderobe shafts and rises to provide a look-out tower. The keep is complete nearly to the roof, but the top floor is half gone and all castellations are missing. The curtain is complete to the wallwalk, but without castellations except for a few surviving by the keep.
The Woodstock Tower was fully restored by J R Cobb and was converted to a house. It is a square three storey tower over a basement gateway, but the corners are chamfered off on the outer face; these chamfers have broach stops. The main face has a pointed arch gateway, a square window above and a smaller rectangular window above this. The tower top has a machiciolated and castellated parapet all complete. The arch of the postern is said to be inscribed for Thomas of Woodstock, son of Edward III. The curtain is complete to the wallwalk, but without castellations in the first section. It then has several windows into now vanished buldings and a major breach on the east side of the castle.
The South East Tower is largely complete externally including castellations. It is a semi-circular tower with a battered base. The curtain is complete to the wallwalk, but without most castellations. The first section is pierced by the first floor windows to the Great Hall. Three large 2-light windows of the mid-C14 with mullion-and-transom and cusped heads. Some castellations to this section of the wall. The final section of curtain before the Great Gatehouse has windows for the private apartments on two floors, including another 2-light mullion-and-transom one on the upper floor.
Elevations to the bailey:
The interior of the Great Gatehouse is two storeyed in stone, with a recessed central archway with two 8-pane windows on either side in projecting frames as before. Four more windows on the floor above; the parapet rises into two tall stone chimneys. The house rises on either side of the upper floor and behind the parapet into an attic with gabled roof behind. All this is of the 1890s as is most of the stonework. The taller flanking towers of the gatehouse rise at the back. The house is in red brick with pseudo timber framing and with timber mullioned windows. A stairway rises on the right hand side to the Great Hall, the entrance to the private apartments is in the building on the left. The curtain is complete to the wallwalk with a restored staircase.
The South West Tower was roofed and given rooms in c1890. It has a 3-light oriel window on the first floor. The curtain is complete to the wallwalk.
The Keep is complete apart from the top storey. It has a first floor entry, and a roof of c1890. The curtain is complete to the wallwalk.
The Woodstock Tower has a basement archway, a first floor entrance, several small windows and a castellated parapet with chimneys disguised as a corner turret. The curtain is complete to the wallwalk but it includes two fireplaces to now demolished lean-to buildings. There is a large breach in the wall on the east side.
The South East Tower has an inserted modern floor, but is roofless.
The curtain has the remnants of the hall undercroft and the interior faces of the Great Hall windows. The private apartments are a two storey gabled house of the 1890s in red brick with pseudo timber framing and tiled roofs. Modern gabled projection on the ground floor, 5-light canted oriel on the upper floor, roof with half hip.
The bailey garden contains a well with dwarf stone wall surround and a large iron naval cannon from H M S Foudroyant.