Abbeycwmhir is a village situated amongst the Cambrian mountains in the county of Powys. It sits near the Clywedog River clustered around the ruins of the abbey built here in 1143. Although it was never completed, it was still the largest abbey in Wales and only the naves of York, Winchester and Durham's cathedrals were longer than Abbeycwmhir's 242 feet.

Leland writes, 'No chirch in Wales is seen of such length, as the foundation of Walles there begon doth show, but the third part of the works was never finished. All the howse was spoiled and defaiced by Owne Glendour'. Indeed, in 1401 Owain Glyndwr, the rebel Welsh prince of Wales, sacked the monastery and perhaps this was the reason the building was never completed. During an excavation in 1827, the abbey unveiled many exciting things: ornamented leadwork, carvings, a stone coffin lid with a Latin inscription, two pennies of Edward II and human bones.

Perhaps the most interesting fact about Abbeycwmhir is its involvement with Llywelyn the Last. After being killed at nearby Cilmeri, his head was sent to London, where it was displayed for a day as a way to mock the Welsh. It is believed, however, that his body was carried to Abbeycwmhir and buried under the High Altar.

Abbeycwmhir Hall overlooks the ruins of the abbey. The hall, which sits in 12 acres of land, was built by Thomas Wilson in 1834 and expanded in 1869 by the Philips family. Tours of the hall and grounds are led by the current owners along with volunteers from the village.