Ancient Monuments

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Coed Newydd Boiling Mounds & Smelting Hearth

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

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Latitude: 53.3486 / 53°20'55"N

Longitude: -4.2693 / 4°16'9"W

OS Eastings: 249037

OS Northings: 385926

OS Grid: SH490859

Mapcode National: GBR HMTV.K3M

Mapcode Global: WH42G.D366

Entry Name: Coed Newydd Boiling Mounds & Smelting Hearth

Scheduled Date:

Source: Cadw

Source ID: 3282

Cadw Legacy ID: AN103

Schedule Class: Domestic

Category: Burnt mound

Period: Prehistoric

County: Isle of Anglesey (Ynys Môn)

Community: Moelfre

Traditional County: Anglesey


The monument consists of the remains of three burnt mounds, probably dating to the Bronze Age (c.2,300 BC - 800 BC) and an iron smithing site thought to date to the Romano-British period (AD 43-400). All lie on low-lying ground beside a small tributary of the Afon Lligwy.

A burnt mound is an accumulation of burnt (fire-crazed) stones, ash and charcoal, usually sited next to a river or lake, with a hearth and/or some form of trough or basin capable of holding water either within the mound or adjacent to it. At these locations it is thought that heated stones were used to boil water, primarily for cooking, and that over time, discarded stones formed a mound around the central hearth or trough. These burnt mounds are of typical horse-shoe shape with central rectangular hearths and may be contemporary with enclosed homesteads on the ridge to the S. Mound A was excavated in 1912, and mound B in 1913, mound C has not been excavated.

The 'smelting hearth' was partially excavated in c.1919-1920, and despite being referred to as such in the original excavation report, the excavator's careful description makes it clear that what was discovered was evidence for iron smithing; smelting is the extraction of metal from its ore by a process involving heating and melting, while smithing is the treatment of metal by heating, hammering, and forging it. The smithing site is situated within a rectangular stone-walled enclosure, measuring c.6.5 m by 3.7 m internally. Excavation revealed two large stones set into the clay floor not far from the E corner. The floor was largely covered with fragments of coal and coal dust, bound together with iron rust; among lumps of slag two forged iron bars were discovered.

The monument is of national importance for its potential to enhance our knowledge of prehistoric domestic and industrial practices. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. Despite excavation in the past the structures may still be expected to contain archaeological information concerning chronology and environmental evidence. The importance of this monument is further enhanced by the group value of the various parts and their proximity to other prehistoric and Romano-British sites.

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

Source: Cadw

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