Bryn Seion Presbyterian Chapel

Bryn Seion Presbyterian Chapel is a single-storey building designed in a classical style, constructed from local red brick. The main decorative features include pilasters, a cornice, and surrounds made of terra-cotta. The front has three bays with a pedimented gable, where the bays are divided by plain pilasters and the pediment is interrupted by a key-blocked arch that springs from the inner pilasters. Each outer bay features a tall round-headed window, while the central bay contains a round-headed doorway with small triple round-headed windows above. The entrance has paired three-panel doors topped with a semi-circular fanlight. The spandrel panel of the pediment arch is adorned with floriated terra-cotta tiles, and there is a stone name plaque in the center. The pediment and string-course are topped with terra-cotta ball finials. The return elevations also have three bays, featuring tall round-headed sash windows in a generally simpler design. At the back of the chapel, there is a single-storey schoolroom, also made of red brick.

The chapel remains largely unaltered, except for the removal of pews. The entrance lobby, which has a decorative ceramic tile dado, is recessed into the main body of the chapel. Inside, there is a flat floor and plastered walls that feature inscribed 'ashlar-work' and a pine dado, with a stone arch located behind the pulpit. The ceiling consists of three bays with decorative ceiling roses surrounding wood ventilators, and the bays are separated by pine boarding. The chapel also includes a carved wood pulpit and a deacons' 'great seat'. The plain schoolroom at the rear has timber roof trusses, and the staging has been removed.