Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Carn Biga, Pumlumon Farw/Plynlimon

A Scheduled Monument in Trefeglwys, Powys

Approximate Location Map
Large Map »
Street or Overhead View
Contributor Photos »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 52.4948 / 52°29'41"N

Longitude: -3.7243 / 3°43'27"W

OS Eastings: 283031

OS Northings: 289939

OS Grid: SN830899

Mapcode National: GBR 97.HX9X

Mapcode Global: VH5BM.DKGC

Entry Name: Carn Biga, Pumlumon Farw/Plynlimon

Scheduled Date:

Source: Cadw

Source ID: 2631

Cadw Legacy ID: MG110

Schedule Class: Religious, Ritual and Funerary

Category: Round cairn

Period: Prehistoric

County: Powys

Community: Trefeglwys

Traditional County: Montgomeryshire


The monument comprises the remains of three stone-built round cairns, probably dating to the Bronze Age (c. 2300 - 800 BC). Items 'A' and 'B' form a pair located on a slight summit on a high plateau above the NW-facing flank of Plynlimon Fawr and overlooking Afon Hengwm to the N. Item 'C' is located 120m to the NNW of Item 'B' on a local knoll. Item 'A' is the southernmost cairn of the pair and is roughly circular in shape on plan. It measures 2.5m in height and 13.5m in diameter. Item 'B' is located 15m to the NNE of Item 'A'. It is circular in shape on plan and measures 2.5m in height, 17m E-W and 15m N-S. Item 'C' measures 0.5m in height, 5m N-S and 3m E-W. There is a pronounced 'tail' of cairn material downslope to the E. The remains of a possible kerb are preserved on the N side.

The monument is of national importance for its potential to enhance our knowledge of prehistoric burial and ritual practices. The feature is an important relic of a prehistoric funerary and ritual landscape and retains significant archaeological potential. There is a strong probability of the presence of both intact ritual and burial deposits, together with environmental and structural evidence. The importance of the monument is further enhanced by the group value it shares with neighbouring cairns.

The areas to be scheduled comprise the remains described and areas around within which related evidence may be expected to survive. Items 'A' and 'B' are centred on Area 'A' (NGR SN 83037 89928). It is roughly oval in shape on plan and measures 58m NNE-SSW by 30m transversely. Item 'C' is centred on Area 'B' (NGR SN 82982 90043). It is circular in shape on plan and measures 15m in diameter.

Source: Cadw

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.