Capel Sion was the former Welsh Baptist Church in Llanfyllin, though it has now been converted into residential accommodation.
The chapel was founded and first built in 1836, then rebuilt in 1877. The latter date is shown on the datestone on the apex of the building. The side walls of the chapel are built from yellow brick, now painted, while the gable walls are of red brick, with detailing in yellow and black brick. Sion was designed by architect Richard Owens of Liverpool and built in the Simple Round-Headed style with a gable entryplan, a central segmented arched doorway with yellow brick surround and terracotta dressings. Above the door there is a triplex of semi-circular headed windows with a circular light in their head and a tall rectangular light below. To either side are windows with tall semi-circular arches. Along the side walls, the windows are square-headed. Sion closed during the late 1990's.

RCAHMW, November 2010