Ancient Monuments

History on the Ground

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

Trefflys Burial Chamber

A Scheduled Monument in Pencaer (Pen-caer), Pembrokeshire (Sir Benfro)

We don't have any photos of this monument yet. Why don't you be the first to send us one?

Upload Photo »

Approximate Location Map
Large Map »

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: 51.9732 / 51°58'23"N

Longitude: -5.0501 / 5°3'0"W

OS Eastings: 190599

OS Northings: 234921

OS Grid: SM905349

Mapcode National: GBR CG.KXQD

Mapcode Global: VH1QL.FN2P

Entry Name: Trefflys Burial Chamber

Scheduled Date:

Source: Cadw

Source ID: 3351

Cadw Legacy ID: PE044

Schedule Class: Religious, Ritual and Funerary

Category: Chambered tomb

Period: Prehistoric

County: Pembrokeshire (Sir Benfro)

Community: Pencaer (Pen-caer)

Traditional County: Pembrokeshire


The monument comprises the remains of a chambered tomb, dating to the Neolithic period (c. 4,400 BC - 2,900 BC). Chambered tombs were built and used by local farming communities over long periods of time. There appear to be many regional traditions and variations in shape and construction.

The burial chamber, known locally as Ffyst Samson is situated in open moorland near rock outcrops alongside an old disused field wall. It has a large capstone measuring 2.25m in length, 1.35m wide and is 0.45m thick, which is balanced on two tall sidestones with pointed tops. The uprights stand opposing each other 2m apart. The northern sidestone measures, 1.05m tall and 1.2m wide whilst its counterpart is 1.2m tall and also 1.2m wide. A low stone platform around the chamber is clearly visible, measuring 10m along its northwest-southeast axis, it is 6.2m wide and has a maximum height of 0.4m; it is constructed of stone boulders and has a clearly defined eastern edge. The north western edge of the mound is concave. Within the burial chamber the ground surface forms a depression 0.3m deep compared to the surrounding cairn.

The monument is of national importance for its potential to enhance our knowledge of prehistoric burial and ritual. The monument is an important relic of a prehistoric funerary and ritual landscape and retains significant archaeological potential, with a strong probability of the presence of both intact burial or ritual deposits and environmental and structural evidence, including a buried prehistoric land surface. Chambered tombs may be part of a larger cluster of monuments and their importance can further enhanced by their group value.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.

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.