Sunk in 1867, Bersham Colliery's first shaft was on the site of what was an old brickyard, writes Nick Bourne from the webteam.
It was always a hard pit to work. It was wet, some coal seams were just 2ft high, and there were problems getting coal up to the surface quickly.
In 1880 eight men were killed in an explosion with a ninth man dying from his injuries a week later. A memorial to the men can be seen in Rhostyllen Church. And a docu-ballet about the tragedy was first performed in early 2009 by The Ballet Pod from Chirk.
A second near disaster was averted when a big fire threatened the pit in 1937.
By 1902 the original owners, the Barnes family from Liverpool, employed 675 men below ground and 94 more at the surface.
At its peak, Bersham - originally called Glanrafon Colliery - also had more than 100 ponies stabled underground.
The effect of mining at Bersham was felt far beyond the shadow of the towering winding gear. Structural damage was caused at nearby Erddig Hall.
Bersham Colliery eventually closed in December 1986, with the loss of 480 jobs, the last pit to close in the so-called Denbighshire coalfield, between Oswestry and Wrexham. [Point of Ayr on the North Wales coast was the region's last pit, closing in 1996]
Today, Bersham Colliery is a mining museum including the former engine house and the last headgear still standing in the North Wales.
The headgear - a legally protected ancient monument - came from nearby Gatewen Colliery and was brought in as a replacement for the No.2 Shaft in 1930 after fire destroyed the former timber-built structure.
The headgear helped to lift men, equipment and the coal up from the coalface 1,269ft / 387m below ground.
In 2007, historic monuments agency Cadw won its bid to preserve the coal tip near due to its heritage value, reported BBC Local News at the time.
