This small church, in Early English Gothic Revival style, known as the Cathedral of the Valley, was built in 1862-3 by Charles Buckeridge for the Revd Gilbert Harries. It is built of snecked, rock faced Pennant sandstone with red brick dressings and banding, a very deep unbroken roof of Welsh slate with overhanging eaves swept down low over the aisles, and metal cruciform finials. Its plan comprises nave with aisles each side, steeply gabled small west porch, and chancel with curved apse. The chancel roof, conical over the apse, is slightly stepped down. The windows are mostly lancets with moulded brick hoods.
The interior is polychromatic, achieved with contrasting banded brick, painted render, brick and stone. The roof is boarded, more decorative and cusped to the chancel, and some fittings for former gas chandeliers are still present. The three bay aisle arcades have pointed arches which are two ordered of contrasting red brick and white painted stone, the piers circular with moulded caps, clustered at the ends.
Other interior features include, near the west door to the south, a deep immersion baptismal pool of stone, brick and tile, with an inset cross in the tiled floor; a large square bowled font; a stone pulpit with open canopywork at the northeast of the nave; part parquet floor reputedly made from railway sleepers; and the chancel richly furnished with decorative crested wood panelling and choir stalls with poppy heads, a refurbishment dating to around the time of the first World War.