Governor's House and Old Prison and Chapel and Exercise Yard and Enclosing Wall

The complex comprises a Governor’s House, an Old Prison, a Chapel, an Exercise Yard, and an Enclosing Wall, now serving as the City Magistrates’ Courts and Lincolnshire Archives Office. The Governor’s House, dating to 1787, was designed by John Carr and William Lumby, while the Old Prison was constructed in 1847 by Nicholson & Goddard. The buildings are primarily brick with stone dressings and have hipped slate roofs.

The Governor’s House features a plinth, a blind arcaded ground floor, a first-floor sill band, quoins, an eaves cornice, and a parapet, with five side wall and five ridge stacks. It is three storeys high and comprises a seven-bay central section flanked by two-bay wings. The central openings have rusticated surrounds. The second-floor windows are largely barred, and the rest are sash windows with glazing bars. The wing ends have regular fenestration, with some blank openings.

The Old Prison, built in 1847, is three storeys high with coped gables and two large ridge stacks. It has chamfered, segment-headed, barred windows. The south side has a central, three-storey canted bay window with a parapet, featuring eight iron-framed glazing bar windows on each floor. Flanking this bay window are stone-coped brick walls with two segment-headed doorways. Traces remain of walls that formerly divided the exercise yard into sectors. At the west end is a full-height canted bay window with stone mullions and iron glazing bars, containing a central, segment-headed door. The north side features a two-storey canted bay window and regular fenestration with some blocked openings.

The single-storey Chapel connects the Governor’s House to the Old Prison. The semicircular ashlar enclosing wall has a chamfered stone coping and five segment-headed doorways.

Internally, the Governor’s House features cantilevered stone dogleg stairs with iron balusters, beaded panelled doors with glazing bar overlights, and many doors have peepholes. The Chapel has a unique arrangement of tiered, linked individual cells for prisoners. The Governor’s House previously functioned as a debtors' prison. The buildings demonstrate significant changes in prison design detail and philosophy. Stop-chamfered spine beams with run-out stops are present.