Ancient Monuments

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Castell Henllys

A Scheduled Monument in Nevern (Nanhyfer), Pembrokeshire (Sir Benfro)

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Latitude: 52.0178 / 52°1'3"N

Longitude: -4.7454 / 4°44'43"W

OS Eastings: 211710

OS Northings: 239040

OS Grid: SN117390

Mapcode National: GBR CW.H1KS

Mapcode Global: VH2N0.PKN1

Entry Name: Castell Henllys

Scheduled Date: 5 April 1950

Source: Cadw

Source ID: 3714

Cadw Legacy ID: PE175

Schedule Class: Defence

Category: Hillfort

Period: Prehistoric

County: Pembrokeshire (Sir Benfro)

Community: Nevern (Nanhyfer)

Traditional County: Pembrokeshire


The monument comprises the remains of a defended enclosure, which probably dates to the Iron Age period (c. 800 BC - AD 74, the Roman conquest of Wales). It occupies an inland promontory to the northeast, east and south of which steep and rocky valley side c 20m high provided natural protection. The easily approachable northern and northwest western flanks are defended by two 140m long bank and ditch ramparts. The more massive inner rampart stands c.2m - 3m above the interior and c.5m above an outer ditch. The outer rampart has a bank rising c.3m above the ditch on its inner face and c.4m above the exterior with no obvious trace of a ditch on the outside. The entrance lies at the southwestern terminals of the ramparts where they stop short of the steep valley side. The slightly domed, triangular-shaped interior measures 95m southeast-northwest and 75m southwest-northeast. An annexe which lies to the northwest is defined by a bank c.1m high with traces of an external ditch; it measures c.125m southwest-northeast and 45m southeast-northwest. Excavations over 25 years from 1981 throughout the entire enclosure interior revealed a series of roundhouses and other structures. The complex entrance arrangements were also excavated together with large portions of the ramparts. Artefacts and radiocarbon dates indicate occupation from the early 4th century BC to the 1st-2nd century BC. The annexe, also excavated, revealed occupation during the Romano-British period. A chevaux-de-frise associated with the original enclosure was uncovered below the annexe bank.

The monument is of national importance for its potential to enhance our knowledge of later prehistoric defensive organisation and settlement. The site forms an important element within the wider later prehistoric context and within the surrounding landscape. The site is well preserved and retains considerable archaeological potential. There is a strong probability of the presence of evidence relating to chronology, building techniques and functional detail.

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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