Capel Rhondda, including attached Sunday school

This is a classical style chapel with an attached Sunday school, dating from the 18th century. The chapel is constructed of snecked, rock-faced stone with lighter freestone dressings and a slate roof. The symmetrical front has three bays, with a central doorway topped by a splayed head with a freestone key and a floating pediment. The double-panel doors incorporate diagonal boarding and are set beneath a margin-lit overlight. The outer bays have round-headed doorways with keystones, margin-lit overlights (replaced on the left side), and doors similar to the central doorway. Above are a plain sill band and a thin impost band. Three blind arches frame round-headed windows within freestone architraves. The central bay features a double pair of windows beneath a tympanum bearing an inscription. The windows have iron-framed glazing (replaced in the left-hand bay). A moulded cornice defines a pediment, which has three stepped vents in the centre and round vents to the sides.

Rounded stair turrets are set back at the ends. These have round-headed windows with margin-lit glazing on the left side, and replaced and partly obscured on the right side by the later Sunday school. The turrets are lower than the main chapel and have plain corbel tables. The side walls project slightly from the turrets. The left side wall, built of random rubble, has four windows, all replacements within original openings and with segmental-headed tops in the lower section and round-headed tops in the upper section, all with stone sills. The right side wall is obscured by the Sunday school but displays a round-headed window in the upper right corner, similar to the left side wall. The rear elevation is of random rubble.

The Sunday school, attached to the right, is in a free classical style, built of snecked, rock-faced stone with lighter freestone dressings, quoins and a slate roof. The three-bay front features round-headed windows with keystones on the left and right. A central, pedimented doorway has double doors with fielded panels and a small-pane overlight, with an inscription on the pediment marking its opening in 1905. The quoins are rounded to three-quarter height. The pedimented gable has an inscription tablet. The right side is roughcast, with a brick eaves stack and a small-pane window in front of the adjoining Chapel Cottages. The rubble-stone rear has plain windows with brick surrounds above a roughcast lean-to.

Inside the chapel the vestibule has a coloured-glass panel opposite the main door and half-lit doors leading to the main chapel. A three-sided raked gallery is supported by fluted cast iron columns with foliage capitals, and has a boarded gallery front. The boarded panel ceiling features a central ornate ceiling rose. The pulpit has been replaced and is flanked by steps with turned balusters and newels. The baptistery is located in front of the pulpit, where the set fawr has been removed. The pews have moulded ends. The large organ behind the pulpit was built by Blackett & Howden of Newcastle & Glasgow.