Ancient Monuments

History on the Ground

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

Cefn-Isaf Burial Chamber

A Scheduled Monument in Llanystumdwy, Gwynedd

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: 52.9439 / 52°56'37"N

Longitude: -4.2583 / 4°15'29"W

OS Eastings: 248352

OS Northings: 340886

OS Grid: SH483408

Mapcode National: GBR 5J.LJ38

Mapcode Global: WH44D.K8GH

Entry Name: Cefn-Isaf Burial Chamber

Scheduled Date:

Source: Cadw

Source ID: 3154

Cadw Legacy ID: CN003

Schedule Class: Religious, Ritual and Funerary

Category: Chambered tomb

Period: Prehistoric

County: Gwynedd

Community: Llanystumdwy

Traditional County: Caernarfonshire


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 consists of a capstone resting on four supporters. The chamber, which is open to the southeast measures 2.4m along its axis from northeast to southwest and 1.8m in width at its northeast end, the internal height is 1m. The northeast end consists of two pillars, each c. 1.1m in height and 0.75m wide, the northernmost stone leans badly inwards; the southwest end was probably similar but only one pillar remains. The northwest side consists of a single slab 3.2m long and 1m high, set on its edge and also leaning slightly inwards. The fourth upright at the west corner is 1.1m in height and 0.5m wide. The domed capstone has a flat underside, with a maximum thickness of 1m and in plan is roughly rectangular measuring 3.5m in length and 2.75m wide, with the south corner broken off.

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 be further enhanced by their group value.

The scheduled area comprises the remains described and an area 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.