Tyn y Gongl Cottage, including attached boundary wall and gate piers

Tyn y Gongl Cottage is a 2-storey house with 2 windows, featuring rendered walls and a slate roof. It has a central roughcast chimney stack, and the left side of the roof has a lower ridge line. The right end of the cottage connects to the rear extension of No 1 Castle Street, which includes a passage leading to a rear courtyard. The entrance on the right side has a mid-20th century half-glazed boarded door. To the left of the entrance are two tripartite 12-pane hornless sash windows on the lower floor, with a similar window on the upper right and a blocked window on the upper left. The left gable end has a 12-pane sash window in the upper storey, which is positioned beneath a plain drip mould. The rear of the cottage features a flat-roofed 2-storey projection. There is also a 1½-storey rear wing, facing the courtyard behind No 1 Castle Street, with rendered walls and a slate roof. This wing has a boarded door with a blocked opening to its left, flanked by replacement windows, and includes an added raked half-dormer on the right with a 2-light window.

Attached to the left gable end is a rubble-stone wall that includes an Edward VII letter box, leading to gate piers. The left-hand pier has lost its cap and there are boarded doors. The building has not been inspected.