The administrative area of the community extends over a wide area of sparsely populated land, and extends south beyond the watershed to include the highest part of the River Taff and the Beacons Reservoir.

Much of its northern boundary is formed by the River Usk.

The peak Pen y Fan (886 m) is at the eastern boundary of the community.

The main (but small) villages in the Community are Libanus and Llanspyddid.

In 2011 the population of Glyn Tarell was 633, with 14.7% of them able to speak Welsh.