St Mair's church is situated on the south-east side of Hermon Road. It is dedicated to Mary and her mother, St Ann.
It is a rendered building with a slate roof, and externally appears to consist of nave and slightly narrower chancel under a single roof, gabled north-west porch, and a single bellcote towards the west end. The church is lit through simple arched and rectangular windows. The building is shown on the first-edition Ordnance Survey map of 1889.
Sources:
http://www.geograph.org.uk/photo/828835
Google Street View, June 2011.
Ordnance Survey County Series 25-inch map: sheet Caernarvonshire XII.9, edition of 1889.

RCAHMW, 11 March 2016

Information received April 2020:

'St Mair's church closed many years ago and the congregation moved down the hill to St Ann's church. When St Ann's church closed because it became unsafe, it was found to be cheaper and easier to refurbish the old St Mair's rather than St Ann's, so that was done, and the joint congregation moved back up the hill'.