Gatehouse to Great Porthamel

The Gatehouse to Great Porthamel is a two-storey structure built in the late 15th century, constructed of red sandstone with some lighter stone accents and topped with a stone slate roof. It features wide, 4-centred carriage arches at both the front and back, each with hood moulding. The outer arch includes a segmental inner arch that allows for the closing of gates. The ashlar sides display scars from the precinct wall, which originally had a wall walk and parapet that remained until at least 1911. On the north side, there is a large window from the stair, while the upper floor is adorned with 2-light windows that also have hood moulds. The gatehouse is topped with a crenellated parapet that steps up to accommodate the head of the stair in the northeast corner, and it has a pyramidal roof behind 19th-century timber gates, along with carved gargoyles.

Inside the carriageway, the walls are rendered, and the vault is supported by ribs that spring from stilted round-moulded corbels. These ribs feature an ogee and hollow chamfer. There is a chamfered door to the stair on the north wall, which leads past a large window to the first-floor chamber. This chamber contains 2-light windows with square heads, set in, with spandrels that have outer casement mouldings. The original ferrumenta is present, but there is no glazing line. A fireplace is located within a depressed arch set in a chimney breast that is slightly forward of the south wall, complete with a relieving arch above. The wall stair continues up to the slabbed wall walk.