Trinity College (original range with additions)

Trinity College comprises college buildings constructed in various phases from the 14th century onwards, with substantial additions in the 19th and 20th centuries.

The main range faces south and is built of rubble stone with tooled sandstone quoins and Caen limestone dressings, beneath steep slate roofs with altered stone chimneys. It rises two storeys with an attic storey. The design follows severe 14th century Gothic style, with an octagonal lantern originally open (now closed in copper sheet) running along the ridge, and flanked by coped gabled projections. At the left end is the principal's house; at the right end is a former chapel, with the 1931 chapel aligned north-south connecting to its side wall.

The main range displays seven coped-gabled eaves dormers with narrow paired ogee lights and tilting latticed heads. Large stone chimneys stand at right angles to the wall face at each end. The first floor features fourteen narrow ogee cusped single-light windows linked by a sill course. The ground floor has three pointed traceried two-light windows to the left, then three square-headed longer cross-mullioned windows with cusped top lights, hoodmoulds and relieving arches. A doorway to the right has similar square head and top lights over a pointed chamfered doorway with a ledged door and iron hinges. The cusping of the top lights is ogee. The plinth steps up under the three left windows. The roof is hipped at the north end down to a lower ridge of the projecting right gable.

The right gable contains a large first-floor four-light window with flat head, hoodmould, cusped top lights and mid-height transom, set above a similar five-light ground floor window divided 1-3-1, with a string course stepped over as a hoodmould. Ground floor buttresses stand on each side wall.

The left gable has a three-light window to the attic, two cusped single-light windows on the first floor, and a three-light window on the ground floor with relieving arch.

The principal's house projects to the left with a parapet on the east side and right half of the south front, and a gable to the south front left. The east side has a single-light and two-light window on the first floor, and on the ground floor a shouldered centre doorway with a ledged door and strap hinges flanked on each side by stone-mullioned windows with ogee cusping and iron lattice glazing, set within an added lean-to conservatory. The south end has a single light over a two-light to the right, and three-light windows on each floor under a gable to the left, with shaped heads to all but the single light; 20th-century aluminium glazing is now present. The west side has an external chimneybreast to the right, gables centre and left over three-light windows, and a ground floor centre mullion-and-transom window with cusped heads to the lights. A 20th-century conservatory stands to the right. Stone chimneys crown the ridge and north end.

To the right of the right gable stands the first chapel, low and modest with a centre buttress and two square-headed transomed and mullioned windows with cusped top lights.

The 1931 chapel stands at right angles to the ante-chapel in Decorated Gothic style with ogee tracery. It is built of rock-faced local sandstone with Yorkshire Morley sandstone quoins and Doulting stone dressings. The structure comprises a nave and chancel with coped gables and cross finials, side-wall parapets, pointed windows with hoodmoulds, and buttresses between bays. The south side features two nave bays with two-light windows, a plinth, and moulded string courses at sill level and under the parapet. A similar but lower two-bay chancel follows, with single lights and an east end of three lights flanked by two single lights, the sill course stepped under the three-light and over a blank plaque. The north side has two chancel bays and six nave bays. End buttresses are gabled. The west end displays a fine window of two lights closely flanked by single lights all under a big pointed hoodmould linked to the parapet string course, with a plaque below the sill course. A single bay projects from the nave south with a moulded pointed south door. The rear of the old chapel has a parallel range with no south windows but a single west light.

Behind the old chapel is a north-east wing appearing to be of two builds: the left section dates to 1847 and has a ridge stack and gable to the right with a small attic casement pair, plus first and ground floor ashlar three-light mullion-and-transom window with cusped heads. A similar two-light appears to the ground floor left and a small two-light under eaves left, with some iron lattice glazing. The 1860 addition to the right has the same ridge line but higher eaves, rising two storeys with a large corbelled centre first floor stack on a mid-buttress. Six two-light flat-headed plain windows are above, and four four-light windows below, all with small-paned iron glazing. Small end stacks complete this section.

At right angles stands the Archbishop Childs Hall, dating to circa 1910, with coped gables and an open square lantern on the roof topped with an ogee dome and finial. The rock-faced stone walls feature ashlar big mullion and double transom windows of two, three and two lights, plus a large canted bay with parapet displaying 1-1-3-1-1 lights. The glazing throughout is small-paned. The end wall has two single lights, a mid buttress and an armorial plaque between. The rear has four two-light windows as on the front.

The rear of the main range displays fourteen first-floor plain square-headed narrow windows and seven hipped dormers with two-light windows and iron glazing. Rear wings to both sides of the rear court show 20th-century alteration.

Internally, an entry tiled hall has a segmental pointed door to the left into an altered library, with plain stone cantilevered stairs with an iron rail further back in the rear hall. A corridor beyond has two Gothic panelled doors to the right and lancets to the left overlooking the rear yard. The chapel ante-room has panelled dado and a blocked large segmental pointed opening into the old chapel. The old chapel comprises two bays with a fine painted roof displaying deep arch-braced scissor trusses on corbels. The ceiling painting dates to circa 1900 with a pretty stencilled motif in each panel. Two kneeling angels and a Crucifixion are painted over the entrance arch, with lettered text along the wall heads. The east end has a blocked window over a pointed arch with double doors into the new chapel. The north wall has one window to the left and a blocked segmental-pointed arch to the right, blocked with a door into the parallel range to the north (a former organ chamber), which has one similar window and a boarded roof.

The new chapel is large with nave and chancel. The six-bay nave has a complex hammerbeam roof of seven main trusses and six intermediate trusses. Six east side windows include one with 1996 stained glass of the Black Book of Carmarthen by Gareth Morgan. A 20th-century north end gallery contains a 19th-century Gothic organ by Nicholson and Company, originally from Wythall Church. A moulded sill course steps over three openings on the west (the entrance door in the centre, a door into the organ chamber of the former chapel, and the nave corner door), with panelling below the sill course. A moulded shafted chancel arch with low walls separates nave from chancel. The chancel features a similar three-bay roof. Cream and green marble floors with green marble chancel steps are complemented by a piscina on the side wall. The end windows contain stained glass: four single lights and one three-light reset from the old chapel, some by Bell of Bristol (whose records for 1873-6 list a three-light Ascension in the east window and side lights of Faith, Hope and Charity and Jesus with Nicodemus). The three-light Ascension remains in place; the two left windows (Feed my Sheep and Follow me) date post-1881, and the two right windows (Christ teaching and Christ stilling the tempest) are possibly also post-1881. A small Gothic open-work pulpit stands on an ashlar base. Pews feature roll-moulded bench ends. A brass eagle lectern dates to circa 1902. Panelled chancel stalls and panelled walls below sill course complete the decoration. The marble altar is grey and buff with inset yellow crosses, behind which stands a reredos with a frame for a hanging.

The principal's house contains a contemporary staircase with scrolled string and two stick balusters to each step. It also preserves 19th-century fireplaces of wood and marble.