Islwyn Level

Also known as	Islwyn Colliery, Martin Level
Location	Argoed, Sirhowy valley, Caerphilly — 51.6861, -3.1810 (approximate)
Commodity	Coal
Type	Coal
Worked	1888–December 1948
Maximum depth	Unknown.
Operators	Islwyn Colliery Co. (1888–1937), E. H. Bennett and Co. Ltd (1937–1947), National Coal Board (1947–1948)

Overview

A small level at Argoed in the Sirhowy valley, opened in 1888 by Edmund Thomas to work the Mynyddislwyn seam. By 1946 it had two adits and 71 men; the National Coal Board took it over in 1947 and closed it in 1948.

History

Islwyn Level at Argoed was opened in 1888 by Edmund Thomas of the Islwyn Colliery Company to work the Mynyddislwyn seam. It was a small house-coal working: seven men, two of them on the surface, in 1896, and eight in 1908, when Edmund Thomas of Maesycymmer owned it. By 1918 the Islwyn Colliery Company employed 20 men under the manager W. J. Barnes, and 26 in 1923.

In 1937 E. H. Bennett and Co. Ltd took over the colliery, with 21 men that year, and in January 1942 it was reported to be raising 150 tons a week. By 1946 it worked the Upper and Lower Mynyddislwyn seams through two adits, Islwyn as the intake and Martin Level as the return, employing 71 men; the firm owned 200 twelve-ton and 28 ten-ton wagons. The National Coal Board took the level over in 1947 and closed it in December 1948, after a final year's output of 12,354 tons.

Geology

South Wales coalfield: the Upper and Lower Mynyddislwyn seams; house coal.

Workings

Two adits by 1946: Islwyn (intake) and Martin Level (return).

Closure

Taken over by the National Coal Board in 1947 and closed in 1948, in December by the NCB list.

What remains

Unknown.

Redevelopment

Unknown.

Nearby mines

Gwrhay Colliery — 0.1 miles (0.2 km) NW
Oakdale Colliery — 0.3 miles (0.5 km) S
Cwrt-y-bella Colliery — 0.4 miles (0.6 km) N
Manmoel Colliery — 1.0 miles (1.6 km) N
Rhoswen Colliery — 1.0 miles (1.6 km) NW

Straight-line distance, within 9 miles (15 km). Show on the map.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

Islwyn Level, Argoed, was opened in 1888 by Edmund Thomas of the Islwyn Colliery Co. to work the Mynyddislwyn seam. ¹
It employed 7 men in 1896, 20 in 1918 and 26 in 1923. ¹
E. H. Bennett and Co. Ltd took over the colliery in 1937. ¹
In 1946 it had two adits, Islwyn the intake and Martin Level the return, and employed 71 men. ¹
Islwyn, Argoed, is listed from 1888 to December 1948. ^2,1

Photographs & further reading

Gwent small mines (Welsh Coal Mines) (reference)

Notes on Islwyn Level and other small Gwent mines.

View source

Sources

(secondary) Gwent Small Mines — Welsh Coal Mines
(secondary) NCB Collieries - Wales — Northern Mine Research Society

Record created: 4 October 2026 · Last researched: 4 October 2026