Scheduled MonumentsWalesCaerphilly Iron Furnace
Post Medieval/Modern · Ironworks

Caerphilly Iron Furnace

Wales
Cadw SAM GM503
Period
Post Medieval/Modern
Site type
Ironworks
Broad class
Industrial
Nation
Wales
The designation
Reference
Cadw SAM GM503
Authority
Cadw
Designated
1997-02-13
Boundary

Scheduled area

© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw

Overview

History & significance

Caerphilly Iron Furnace is a post-medieval ironworks situated in the South Wales coalfield, where the Upper Coal Measures Formation provides the raw materials that made iron production viable in this region. The underlying bedrock of mudstone, siltstone and sandstone is interspersed with coal seams and ironstone deposits, together with bands of ferricrete—all essential resources for smelting and fuel. This geological advantage established the site within one of Britain's most important centres for iron manufacture during the industrial period.

The furnace represents the industrial exploitation of Wales's mineral wealth, when proximity to coal and iron ore made the region intensely competitive for ironworks development. The combination of fuel and ferrous deposits in the Upper Coal Measures Formation, laid down in the Westphalian period of the Carboniferous, created conditions that attracted investment and skilled workers throughout the post-medieval era into the modern period.

The monument is protected by Cadw, the Welsh Historic Monuments service, as a significant record of Wales's industrial heritage. The survival of structural remains at Caerphilly documents the technological and economic systems that transformed the South Wales landscape and made the region a centre of metallurgical innovation and production.

Caerphilly Iron Furnace is a scheduled monument protected by Cadw under reference GM503. View the official record →

About this monument

Questions & answers

What is Caerphilly Iron Furnace?

Caerphilly Iron Furnace is a post-medieval ironworks situated in the South Wales coalfield, where the Upper Coal Measures Formation provides the raw materials that made iron production viable in this region. It is designated a Scheduled Ancient Monument by Cadw under reference GM503.

What period does Caerphilly Iron Furnace date from?

Caerphilly Iron Furnace dates from the post medieval/modern period, and is classified as a ironworks. It is one of over 32,000 scheduled monuments protected across the UK.

Who is responsible for protecting Caerphilly Iron Furnace?

Caerphilly Iron Furnace 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 GM503.

What other scheduled monuments are near Caerphilly Iron Furnace?

Several scheduled monuments lie within 10 km, including Wenallt Camp, Rhiwbina (5 km), Castell Coch (5.2 km), Twmpath, Rhiwbina (5.6 km).

Unlimited access

Everything a full report reveals about Caerphilly Iron Furnace

This page is just one thread. A full Aubrey report pulls together 13 strands of Caerphilly Iron Furnace'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 Caerphilly Iron Furnace

Caerphilly Iron Furnace stands on South Wales Upper Coal Measures Formation, bedrock that formed in the Westphalian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.