Scheduled MonumentsWalesCastell Mawr
Prehistoric · Enclosure

Castell Mawr

Carmarthenshire, Wales
Cadw SAM CM126
Period
Prehistoric
Site type
Enclosure
Broad class
Monument
Nation
Wales
The designation
Reference
Cadw SAM CM126
Authority
Cadw
Designated
1951-07-06
Boundary

Scheduled area

© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw

Overview

History & significance

Castell Mawr is a prehistoric enclosure located in Wales and protected by Cadw under reference CM126. The monument occupies ground underlain by Ashgill Rocks, a bedrock formation of mudstone, siltstone and sandstone laid down during the Ashgill period. This geology has shaped both the landscape and the character of the site itself.

The enclosure consists of an earthwork defence of substantial proportions typical of later prehistoric settlement practices in Wales. The combination of stone-rich Ashgill geology and the site's topography would have provided both material and strategic advantages to its builders and occupants. Such enclosures served defensive, administrative and territorial functions within their communities.

Castell Mawr represents an important record of prehistoric land use and settlement patterns in this region of Wales. As a scheduled ancient monument, it remains an archaeological resource of significant value, preserving evidence of the social organisation and economic activities of Wales's prehistoric inhabitants in its physical structure and surviving earthwork.

Castell Mawr is a scheduled monument protected by Cadw under reference CM126. View the official record →

About this monument

Questions & answers

What is Castell Mawr?

Castell Mawr is a prehistoric enclosure located in Wales and protected by Cadw under reference CM126.

What period does Castell Mawr date from?

Castell Mawr dates from the prehistoric period, and is classified as a enclosure. It is one of over 32,000 scheduled monuments protected across the UK.

Who is responsible for protecting Castell Mawr?

Castell Mawr 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 CM126.

What other scheduled monuments are near Castell Mawr?

Several scheduled monuments lie within 10 km, including Capel Bettws (0.9 km), Castell Bach (2.4 km), Castell Mawr Mound and Bailey Castle (2.6 km).

Unlimited access

Everything a full report reveals about Castell Mawr

This page is just one thread. A full Aubrey report pulls together 13 strands of Castell Mawr'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 Mawr

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