Exterior
Town hall, 2-storey, 3-bay, classical building: Rubblestone originally stuccoed with hipped slate roof and renewed moulded modillion eaves cornice. Later C19 clock turret on roof with open pedimental gable. Front has 3 giant arched recesses at first floor with 3 sunk panels over (the centre one with traces of clock of 1848). The giant arches have stone voussoirs over fine ashlar Palladian windows with Ionic columns. Later C19 or early C20 glazing with marginal glazing bars, stucco still in situ between windows and arch soffits. Windows have ashlar blind balustrades divided by piers, and ashlar continues each side to form band over ashlar ground floor which has entablature and cornice over paired Tuscan columns and pilasters against rusticated walling with matching projecting central portico, the portico of 1860-2, the rest possibly early C19. Outer single pilasters, paired columns to outer side of ground floor windows (aligned with outer sidelight of window above). Windows are recessed, cambered-headed, with horned sashes and sunk panels beneath. The portico has 4 pairs of Tuscan columns, cornice and balustrade, the pairs aligned with side-lights of the centre window and inner side-light of each outer window. Column and pilaster responds, and similar pair of columns and outer pilasters to centre entrance recess with heavy cast-iron gates and side grilles. Matching columns and responds within, and early C20 glazed doors. Portico soffit of very large slightly panelled stone slabs.
Fine C18 lead fluted rainwater head each side of facade, each with downpipe with embossed head on each of 5 lead brackets. Two marble war memorial plaques to Carmarthenshire Royal Engineers within portico.
Each side wall has large first floor blind stuccoed arched panel with a rectangular stuccoed panel over. Ashlar ground floor as on facade, with 3 windows framed by paired columns in rusticated wall with column and pilaster at outer ends framing a narrow windowless bay.
Rear NE wing to Hall Street of 1827-9, stucco, 4 storeys, 3 bays, to same eaves level but with different modillions. Small-paned sash windows, square to top floor, 12-pane to main floors. Ground floor has arched recesses linked by impost band with 2 arched windows and arched door to right. Door has moulded frame, fanlight with radiating tracery and six-panel door with 4 fielded panels. Two basement windows under grilles. There are railings set on a curve in angle. Lead rainwater head with 5 embossed lead brackets to downpipe.
SE rear wing possibly of 1898, of 3 storeys and 2 bays, later C19 with cambered-headed sash windows with marginal glazing bars to upper floors. Ground floor faced with stucco imitating ashlar has channelled pilasters framing recesses with round-headed sash windows, also with marginal glazing bars. Building continues recessed behind Plume of Feathers to asymmetrical end gable.
Rear of main hall has centre curved stair tower with arched windows. Gable to right, rear of 1827 NE wing, with awkward join above stair tower, apparently altered.