Ancient Monuments

History on the Ground

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Trwyn Du round cairn

A Scheduled Monument in Aberffraw, Isle of Anglesey (Ynys Môn)

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Latitude: 53.1825 / 53°10'56"N

Longitude: -4.4673 / 4°28'2"W

OS Eastings: 235226

OS Northings: 367884

OS Grid: SH352678

Mapcode National: GBR 58.3F9H

Mapcode Global: WH434.B8ZL

Entry Name: Trwyn Du round cairn

Scheduled Date: 24 February 2005

Source: Cadw

Source ID: 4175

Cadw Legacy ID: AN148

Schedule Class: Religious, Ritual and Funerary

Category: Round cairn

Period: Prehistoric

County: Isle of Anglesey (Ynys Môn)

Community: Aberffraw

Traditional County: Anglesey


The monument comprises the remains of a burial cairn, probably dating to the Bronze Age (c.2300 BC - 800 BC) and situated on the leading edge of the rocky foreshore on the NW side of Aberffraw Sands. The grass-covered cairn is roughly circular on plan and measures about 9m in diameter and up to 0.6m in height. It has been partially excavated in the past (Houlder 1957; White 1978), the work revealing a well-preserved kerb cairn coincidentally overlying flint debris and occupation material of early Mesolithic date (c.7000 BC).

The monument is of national importance for its potential to enhance our knowledge of prehistoric burial and ritual practices. The well-preserved 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. The importance of the site is further enhanced by the recovery of unusually large amounts of early Mesolithic material, occupation material that can be confidently presumed to extend further beyond the limits of the areas previously excavated. Although the topographic association between the two sites is coincidental, the area retains great archaeological potential, the value of which is also enhanced by incorporating the results of earlier investigation.

The area to be scheduled comprises the remains described and an area around them within which related evidence may be expected to survive. It is irregular and measures up to 58m from N to S by up to 46m transversely.

Source: Cadw

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