Ancient Monuments

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Castell Glas Castle Mound

A Scheduled Monument in Gaer (Y Gaer), Newport (Casnewydd)

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Latitude: 51.5665 / 51°33'59"N

Longitude: -3.0087 / 3°0'31"W

OS Eastings: 330180

OS Northings: 185776

OS Grid: ST301857

Mapcode National: GBR J5.DFX7

Mapcode Global: VH7BC.SWSH

Entry Name: Castell Glas Castle Mound

Scheduled Date:

Source: Cadw

Source ID: 2414

Cadw Legacy ID: MM190

Schedule Class: Defence

Category: Motte

Period: Medieval

County: Newport (Casnewydd)

Community: Gaer (Y Gaer)

Built-Up Area: Newport

Traditional County: Monmouthshire


The monument comprises the mutilated remains of a medieval motte on almost level ground on the western bank of the Ebbw, overlooking its lowest crossing point which suggests that it was established soon after . The mound has been reduced to around 1.5m high and 35m by 25m in size and any ditch has been backfilled. An early 20th century sketch by Dowman shows both the motte ditch and a bailey extending SE towards the river. Maesglas or Greenfield lay in the medieval manor of Ebboth, held under the lordship of Gwynllwg (later Newport). It may be the Castell Behan or Bychan mentioned by Leland and in 1586 Thomas Churchyard devoted two stanzas to 'Greenefield' in his Worthiness of Wales, describing it as 'A goodly seate, a tower, a princely pile'. and was used as a country retreat of the Duchy of Lancaster in the 15th century, Jasper Tudor being introduced to his prospective wife at Maesglas. It was sold in 1622 and by 1645 was said to have “disappeared”. When Coxe visited in 1800 the remains included the 'high' mound and a medieval range with a square tower and a possible hall block with a “fine Gothic entrance”, a “large fireplace” and “several Gothic doors” incorporated into a farm. These were also seen by Dowman as late as 1911 and a door was drawn by W H Greene in the 19th century, early OS editions showing a long range with a projecting porch or tower. These buildings stood over 100m from the scheduled area on the site of the school to the NW but were levelled without record ahead of the construction of the Maesglas Estate by the 1930s.

The monument is of national importance for its potential to enhance our knowledge of medieval domestic and defensive architecture. It retains significant archaeological potential, with a strong probability of the presence of both structural remains and intact associated deposits providing evidence for its development, construction and contemporary material culture.

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

Source: Cadw

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