St. Nidan's Church (Old Church)

St. Nidan's Church, also known as the Old Church, features a western end that is part of a medieval double-naved structure, showcasing Decorated and Perpendicular tracery. It includes a south porch and remnants of a central arcade extending eastward. The walls are constructed from local rubble masonry with sandstone dressings. The western wall was partially rebuilt, likely in 1844, and now includes added buttresses, with two low buttresses on the south aisle and a single diagonal stepped buttress at the northwest corner. The church has a modern slate roof, and the western gable of the south aisle features a double bell-cote and stone copings.

The main entrance is through a chamfered basket-headed doorway leading to the south porch, which connects to a similarly designed south door of the church. The north wall has a pointed arch-headed doorway at the western end, consisting of two chamfered orders, a moulded label, and carved human-head stops. There is a paired window with trefoil-headed lights at the eastern end, also with a moulded label. Both the north and south aisle gables have pointed arched Perpendicular tracery windows; the south aisle contains re-set 15th-century tracery in the upper part, while the rest of the tracery is a modern replacement.

The central arcade consists of six bays with four-centred arches made of two hollow-chamfered orders, supported by octagonal piers and semi-octagonal responds featuring chamfered capitals and plain bases. The second pier from the western end is embedded in a 19th-century cross wall. The double-naved western portion has a 15th-century roof with four bays, displaying exposed arch-braced trusses supported on sandstone corbels, along with renewed purlins and rafters. The masonry walls, which were once adorned with scriptural texts, have mostly lost these inscriptions, though part of two verses from the 84th Psalm in Welsh remains visible above the north doorway. Most internal fittings have been removed, and the church now contains fittings from other churches in Gwynedd. The altar is modern, made of Cumbrian granite, with a moulded top and chamfered angles.

The church also houses 17th and 18th-century memorials. Additionally, the eastern wall of the porch features a fluted stone water stoup.