Scheduled MonumentsWalesCastell Rhaglan
Medieval · Castle

Castell Rhaglan

Wales
Cadw SAM MM005
Period
Medieval
Site type
Castle
Broad class
Defence
Nation
Wales
Boundary

Scheduled area

© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw

Overview

History & significance

Castell Rhaglan is a substantial medieval castle located in Monmouthshire, Wales, which represents one of the finest examples of 15th-century military architecture in Britain. The castle was begun in 1432 by William ap Thomas and substantially developed by his son William, Earl of Pembroke, featuring a distinctive hexagonal tower known as the Yellow Tower of Gwent that served as both stronghold and symbol of lordly power. The fortress demonstrates the sophisticated defensive engineering of its period through its concentric plan, elaborate gatehouse systems, and water-filled moat, reflecting developments in castle design during the later medieval period. Castell Rhaglan remained an important military installation into the 17th century and was slighted following the English Civil War, though substantial ruins of its principal structures survive to the present day.

Castell Rhaglan is a scheduled monument protected by Cadw under reference MM005. View the official record →

About this monument

Questions & answers

What is Castell Rhaglan?

Castell Rhaglan is a substantial medieval castle located in Monmouthshire, Wales, which represents one of the finest examples of 15th-century military architecture in Britain. It is designated a Scheduled Ancient Monument by Cadw under reference MM005.

What period does Castell Rhaglan date from?

Castell Rhaglan dates from the medieval period, and is classified as a castle. It is one of over 32,000 scheduled monuments protected across the UK.

Who is responsible for protecting Castell Rhaglan?

Castell Rhaglan is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is MM005.

What other scheduled monuments are near Castell Rhaglan?

Several scheduled monuments lie within 10 km, including Great House Camp (5.3 km), Camp 650m South of Ty Freeman (6.2 km), Ringwork NE of New House (7.3 km).

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Everything a full report reveals about Castell Rhaglan

This page is just one thread. A full Aubrey report pulls together 13 strands of Castell Rhaglan's history, each drawn from the record and mapped to the exact spot:

Overview
An interactive map of the location with every monument and battle plotted, and a plain-language history built only from what the record holds.
Monuments
The legally protected scheduled monuments around the location, each with its period, type and significance.
Battlefields
The battles and sieges fought on this ground, mapped and set on a timeline of the wider conflict.
Roman Britain
The Roman roads, forts and towns near here, and the Iron Age people who held the land before Rome arrived.
Civil War
The Civil War fighting, garrisons and recorded militaria in this area, woven into the arc of 1642 to 1651.
Geology
The bedrock beneath the site, its age and rock type, reaching back hundreds of millions of years.
Local Names
What the street and field names around here actually mean, and the history buried inside them.
Historical Maps
Ordnance Survey maps from the 1800s, layered over the location as it stands today.
Literature
The books, county histories, charters and archives that mention this place, quoted with their sources.
Legal
The protected sites nearby and the metal-detecting, access and treasure laws that apply to this ground.
Spotlight
A deep dive into the most remarkable, lesser-known history of the place, traced back to the record.
Target Zones
For detectorists: the most promising ground to search nearby, ranked by confidence, with what to expect.
Timeline
The whole story of the location told era by era, from prehistory to the present day.
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The ground beneath

The bedrock under Castell Rhaglan

Castell Rhaglan stands on Pridoli Rocks (Undifferentiated), bedrock that formed in the Pridoli. The rock here is mudstone, siltstone and sandstone.