Seion Methodist Chapel was first built in 1820, but its lease expired in 1860 and the congregation bought a plot in the centre of the village to build a new chapel. This new chapel was designed, and its erection superintended, by the architect Richard Owen of Liverpool. It was probably opened during a ceremony on 9-10th August 1875. It is built in the Gothic style with stone walls, slate-roof and gable entry plan. The front facade has a centre gable with coping, kneelers and buttresses with two offsets. The wide pointed giant arch with dripstone encloses has a punched wheel window, over a window of three flat-headed lights with columned mullions. The doorway below has a carved typanum and two doors each of 3 diagonally-boarded panels. To each side of the doorway is a stone plaque. The left hand plaque is inscribed 'Calvinist/ Methodist/ Chapel', and the right hand one 'Erected/ AD/ 1874'. The central gable is flanked by stair turrets with saddleback roofs, the last with lozenge-shaped slates and crest tiles. The front of the turrets have tall lancet openings with punched quatrefoils above tall cusped lights. The side elevations each have three windows with arched heads. The forecourt is enclosed by a dwarf stone wall, octagonal ashlar gate piers, and contemporary iron railings and gates. Attached at the rear is a lower and narrower vestry, "which can be thrown open", thus bringing the seating up to 250. This has a steep-sided slate roof and, in the rear gable, two windows with arched heads.

RCAHMW, December 2010