The Courthouse, The Square, Hillsborough, County Down, BT26 6AG

Hillsborough Courthouse is a Palladian-style former market house and courthouse, built around 1760 and extended around 1820, now serving as a visitor centre. It stands prominently on sloping ground at the centre of Hillsborough's town square, immediately east of Hillsborough Castle, with the Dromore Road and Main Street passing close to the south-east. The building is axially aligned with both Hillsborough Castle and the entrance to Hillsborough Fort, with which it shares group value. It sits at the heart of what is arguably Northern Ireland's most complete Georgian townscape, and its virtually intact exterior and interior — including what is thought to be a complete set of original courtroom fittings — make it one of the best-preserved public buildings of its period.

The building was possibly designed by William Forsyth or James McBlaine, with the later extensions possibly to plans by James McBlaine the Younger. It is part single-storey, part two-storey, and is constructed of granite, sandstone and render. The plan is rectangular, with the long front elevation facing east, comprising three blocks of roughly similar footprint arranged symmetrically. The original central section is itself symmetrical: it has single-storey flat-roofed east and west ends, between which rises a square upper level capped with a shallow pyramidal roof and a square, domed clock tower. Flanking the central block on either side are single-storey hipped-roof pavilion-like outer blocks, which are the additions of around 1820.

The whole building is set on a tall base and projecting plinth. Because the ground falls away to the north-east, the plinth increases in height in that direction. The plinth, base, and lower halves of the pavilion walls are all in cut granite, while the upper halves — and the recessed east and west faces of the central portion — are largely in cut sandstone rising to a parapet adorned with ball finials. The upper level is rendered, with cut sandstone architraves topped either with cornice hoods or tympanums, a sill course, and a projecting eaves cornice with corner urn finials. The clock tower appears to be largely timber-built and features corner pilasters, gold-on-black clock faces on two sides, a projecting cornice with urns (more decorative than those on the main building), and a lead-clad pointed dome with weathervane. The pitched roof sections are covered in natural slate with lead flashings and valleys, while the flat areas appear to have lead coverings. The downspouts are cast-iron and are fitted with decorative fan-like hoppers.

To the east, west and south sides of the building there are large central double flights of steps fronted in cut granite, with decorative iron railings. From the front steps there extends an elaborate lamp fitting. The flights to the south and west were constructed around 1997 to replace the original splayed steps. Set on the plinth along the north, south and east sides are granite planters, also dating from around the 1990s.

The front steps lead to a narrow paved area enclosed with similar railings, beyond which is an arcade of three tall semicircular-headed openings. These have plain architraves in cut granite up to impost level, keystones, and an impost stringcourse that continues around the entire building. The openings are now in-filled with modern plate glass, with the central one incorporating the main entrance. The east faces of the pavilions each have a similar arcade, largely blind except for a semicircular upper window to each opening and a flat-headed doorway to the central arch. The windows have timber frames with Georgian panes, while the doorways have studded timber sheeted double doors. The doorway to the right (north) is reached via a splayed flight of granite steps with curving iron railings.

The smaller upper storey has three flat-headed windows, a tympanum over the middle window and cornice hoods over the others, with horned 6/6 timber sash frames throughout. The other elevations at this level are identical, but with arch-headed louvered openings to the north and south sides of the tower in place of clock faces. The shorter south elevation has an arcade similar to that on the front of the pavilions, but consisting of five arches with larger windows and a doorway to the central opening reached via the double steps; the door is in the same style as those to the front. The west elevation matches the front elevation but without the outer doorways, while the outer arches of the central portion have windows matching their counterparts on the pavilions. The granite face of the steps on this side bears a stone inscribed "EHS 1997", recording the date the steps were altered to their present form. The north elevation matches the south, but without the doorway and steps.

The history of the building is complex and the dates of both the original section and the later additions remain uncertain. The earliest part is thought to have comprised the two-storey central block surrounded by a single-storey arcade, of which the present central recessed bays to the east and west formed part. This is variously dated to around 1760, 1772, and around 1780. The extensions are widely given as around 1810, but evidence suggests they may be a decade later.

In 1744, Walter Harris recorded that Lord Hillsborough had "fixed on a plan for a new town to be built in the form of a large square, with a stately market house in the centre." No building is marked on this site on maps of 1745 or 1755, but a market house of some description was standing somewhere in the town by at least 1763, as it is referenced regularly in Belfast News-Letter notices from April of that year onwards. It is also mentioned, though unfortunately not described, by the Reverend Daniel Beaufort in his diary entry of 17 August 1765. Whether these sources refer to the present structure is unclear. A plan and elevation of "Hillsborough tholsel, Ireland," showing a design very similar to the building as it is believed to have stood before the early 19th-century changes, was drawn up by William Forsyth at some point in the 1770s. This could indicate that an entirely new build was then in prospect and was carried out in that decade or shortly afterwards; that alterations were being planned to an existing structure; or simply that the drawing was produced as a scheme based on the structure as it then stood, to be followed elsewhere. The architecture itself is not inconsistent with the early 1760s or even slightly earlier, and could quite possibly represent the "stately" edifice envisaged in 1744. A Kilwarlin estate map of 1771 is too small in scale to allow any firm conclusion, but the original portion of the current structure does appear to be that shown on William Byers' map of 1788.

The question of dating raises questions of authorship. Forsyth's design is very similar to those produced by James McBlaine (died 1792) for the market house planned for Lord Downshire at Edenderry, County Offaly. James McBlaine worked on Hillsborough parish church in the early 1770s, and according to Charles Brett, someone of that name is recorded as residing in the town in rentals up to 1780 and again in 1787. By the latter date, however, McBlaine was in the employ of Earl-Bishop Hervey at Downhill, so it is likely — as Brett surmised — that this rental entry refers to his son, who was also an architect. The plans for the Edenderry building, which were never executed, are undated, so their role in the sequence of events cannot be determined. Forsyth was clerk of works during the initial stages of the extending and remodelling of Hillsborough Castle in the mid-1790s but appears to have had a less distinguished career than McBlaine; his drawing may therefore simply be an interpretation based on the latter's work. As with the dating, the evidence as it stands is inconclusive.

In October 1795 the building was the scene of a seemingly drink-induced serious affray involving the "Kilwarlin boys." Thomas Lane, reporting the incident to Lord Downshire, states that the tholsel was threatened by the troublemakers but that the high constable, Wright, "behaved nobly," with four ringleaders lodged in the Black Hole. Lane obtained a sergeant's guard from the camp through Lord Doneraile, accompanied the sovereign to every public house to forbid the sale of liquor, ordered the guard to clear the square of those disregarding his admonitions, and reported the night ultimately tranquil. Although this incident does not appear to have resulted in serious damage, Beaufort, visiting Hillsborough again in 1808, described the front of the market house as being "much out of repair" and made a sketch of it. Some remedial work may have been carried out in 1810 or shortly after, as the present clock mechanism dates from that time, but whether the new market and courtroom extensions were added at that point, as Brett believed, is not known. A "Design for Hillsborough Session House" was drawn up by James McBlaine the Younger in January 1819, conceived as a free-standing structure, which would appear to indicate that work was only being contemplated around that time. The enlargements must have been completed by at least late October 1823, however, when the English architect Charles Robert Cockerell made a sketch of the "remarkably well" composition as it now stands.

In the valuation of 1834 the building was recorded as consisting of a "town hall" (the central two-storey section) measuring 35 feet by 35 feet by 26 feet; a "market house" (the south pavilion) at 34 by 62½ by 12 feet; a "courthouse" (the north pavilion) at 34 by 62½ by 12 feet; "piazas" (the arcaded entrance front) at 34 by 11 by 12½ feet; and a "housekeeper's dwelling" (the rear section). The 1837 Ordnance Survey Memoir describes it as "a neat, stone building occupying a space 103 feet long and 64 feet broad. At one end is the sessions court, at the other a market place and between them are the grand jury room and the caretaker's apartments." By the 1862 valuation, the market place is no longer mentioned as such; much of its space had apparently been converted to a workshop for the estate carpenter, with trading confined to its original location on the ground level of the central area, above which was now a "reading and band room." By the mid-20th century the workshop had become the estate office. In 1959 the building was taken into State Care and subsequently refurbished; this work involved the removal of the chimneystacks from the central and northern blocks. The courtroom remained in periodic use until the later 1990s, while the former estate office became a community hall. In 1997 a further refurbishment scheme converted the building to its present role as a tourist information and interpretive heritage centre, with the courtroom itself becoming the main exhibit. The new stone steps to the southern and western sides were added at this time.