Trallong lies to the north of the river Usk on the edge of the Brecon Beacons National Park, Powys, South Wales. The village sits on a minor road, parallel with the A40, between Sennybridge and Brecon. The Usk travels from its source in the Carmarthen Fans mountains to its estuary at Uskmouth, 49 miles from Trallong.

The exact age of St David's Church, Trallong, is unknown but it is believed that a site existed here in the 12th century, and the church has also been recorded in the St David's Episcopal Register in 1513. In 1855 the roof was raised and replaced with stone tiles. Sadly none of the original interior still exists, but there is an old font and an interesting pre-Norman stone which is carved with a large ring-cross on it and a stone lintel with the Ogham inscription carved upon it.