[1] The scattered settlement lies on the south-facing slopes of the Berwyn Mountains in the high upper part of the Tanat Valley, at around 950 feet above sea level.

The church of St. Garmon is thought to be of early-mediaeval origin; it was 'restored' in 1886 to designs by W. H. Spaull of Oswestry.

[1] The area was historically part of the parish of Llanrhaeadr-ym-Mochnant but eventually became a separate township.

[4] There is also a Calvinistic Methodist chapel, Hermon, rebuilt in 1906 in a "curious" Art Nouveau-influenced style.

[5] The academic Griffith Hartwell Jones was the son of a rector of Llanarmon Mynydd Mawr, the Rev.