The colliery was begun in 1907 with the sinking of two shafts, and reached completion in 1911. In 1935, 86 men were employed on the surface and 358 men underground. The seams worked at that time were Meadow Vein, Black Vein, Elled, Big Vein and the Three-Quarter. Unfortunately, the Black Vein Straight North District hit an underground lake in 1937. This meant that the shafts were eventually half submerged, and the pit bottom had to be permanently raised by 39 metres. By the 1960's widespread pit closures also affected the Navigation Colliery, and its gates were finally closed in September 1967.
Closed since 1967, the buildings are Grade II listed. At the time of writing they were still lying dormant despite plans in the early part of 2009 to turn them into apartments.
I visited this site in February 2008, along with some friends on an urban exploration meet-up in South Wales. This was the last explore of the weekend and, despite cold and fatigue, was another excellent place to see and take photos of.
Overlooking the main building (above). If I recall correctly, the buildings were on three levels; the main ones being at ground level whilst the others were on the hillside.
I don't know whether it was because I was shaking from the cold or the exhaustion, but some of my photos were pretty bad from this site, apart from a lucky few.
Finally, some graffiti. I have an ambivalence towards graffiti, especially not liking it on old and historic buildings, but appreciating the artwork when well done. I don't usually take photos of them but the one below looked wonderful against the metal and brickwork.
More photos along with these can also be seen in the Photo Gallery album.