24, Castle Street

No. 24 Castle Street is a building that originally served as a gatehouse and lodge for the castle, dating from around 1800. It has since been converted and extended to function as solicitors' offices. The structure is made of yellow-brown stock brick in Flemish bond, featuring red dressings, with roofs that are Welsh slated and lead flat, concealed behind castellated parapets with stone copings and red brick Tudor-style clustered shafted octagonal chimneys.

The exterior of the building is two storeys high. The right-hand section, which includes two octagonal turrets, was the original gateway to the castle. It featured a high central Tudor arch that was infilled around 1904 and replaced with a four-light wood casement window, which has arched Tudor heads, similar to the two-light window above it on the first floor. The turrets are adorned with machicolations and a Lombard frieze. To the left is the former lodge, connected by a recessed two-storey link that has three-light windows on both the ground and first floors. The higher block to the left retains two original bays, with two three-light windows on the first floor and a four-light window on the ground floor, which features a projecting porch with a Tudor arched opening and a castellated parapet. The building was extended three bays further west around 1904, with the first floor now having three windows, one of which is a double-length window at the center, and two below it, along with a basement window beneath a longer stair window. The rear elevation has been significantly altered with modern windows.

Inside, the building has been much modified during its conversion to office space. The room above the arch has a vaulted ceiling, and the staircase in the 1904 extensions features a close string dogleg plan with a narrow open well, balusters with pulvinated square columns and newels, and a moulded oak handrail. Together with No. 20 Castle Street, this building serves as the headquarters for Longmores solicitors, a family that has provided service to the Borough as Town Clerks and to the County Council for several generations since the 1830s.