We found this fantastic location because of GC1GNE7 by justhejob who yet again took us to a fabulous geocache. He has some details about the mine on his cache page.
Above the Slate Mill is the Trefriw Trails 5 walk where the remains of the cableway, which was used to transport the ore from the Pandora mine at the southern end of Llyn Geirionydd, was lowered to the mill for processing.
There are several tunnel entrances visible from outside the dripping arched cavern opposite the slate mill. Above this is another entrance visible across the slate spoil piles and a small hole in the rock along the Trefriw Trails 5 walk.
Lying in Geirionydd Gorge the access path from the top is along a steep, slippery and rocky path where a stream continues with you for some distance. This leads to a main path at the bottom and a narrow path along the edge of the stream (a tributary to the River Crafnant) and a plank which can be walked to the slate mill and beyond.
The mill and mine were opened to process lead ore by the Welsh Crown Spelter Company in 1900. Both this mine and the Pandora mine proved to be less worthy than originally thought.
On the (visit link
) website are some interesting photographs and some details stating that inside one of the main Klondyke levels is blocked by a concrete barrier. It is thought to have been installed to use the chamber which the tunnel lead to as a "slate-slurry" pit with the waste being dumped down an air shaft. Also due to the nearby Peat Field working quarry some of the levels leading off the main Klondyke Pit are blown up, or concreted-up as it is untopping some of Klondyke's chambers, which are directly underneath.
Wikipedia lists some fascinating details:
'The large main adit is adjacent to the prominent Klondyke Mill at the base of the Geirionydd Gorge. The level has been driven along three parallel N-S lodes although no stoping was undertaken. The following is an extract from an article written in 1997 by Robin Griffiths.
The site of the old Klondyke Lead Mine is dominated by the impressive remains of the old Klondyke Mill. The mine itself consists of one main level adjacent the mill and numerous smaller working following the Geirionydd Gorge upstream, although some of these working are part of the Bryn Cenhadon Mine.
I first visited the site during spring after a visit to the nearby Clogwyn y Fuwch slate mine. On this occasion I just visited the Klondyke Main Adit. The adit numbering system adopted in this article is arbitrary.
On Sunday 1st of December I returned to do a survey. Again I visited the main adit (ADIT 1) which lies immediately across the stream from the mill. The entrance section is quite large and stone lined. The workings basically consist of three passages trending southwards from a cross cut. There does not seem to any great signs of actual lead working despite the fairly extensive passages.
Just upstream from here is the Geirionydd Gorge which is quite a narrow ravine leading up to Llyn Geirionydd. There are numerous small and more extensive workings on both sides of the river here. Small nondescript workings are those Adits marked on the map as numbers 3, 7, 8, 9 and 10.
Adits 2, 3, 4 and 5 are just below some cascades in the river. In fact the entire river drops down a shaft in the river bed and emerges as a foaming cascade from a small mine level (not numbered). Numbers 4 and 5 are linked and lead to a quite large stope which is about 2m high and dips at about 20° to the west. As ADIT 4 enters the stope there is a large timber lined door frame.
ADIT 2 is on the opposite side of the river and is basically a single passage leading to a small stope with a single side branch. The survey shows the passage to go underneath the river onto the opposite bank. This is accomplished because of the climb in river bed above this group of entrances.
ADIT 6 is a short length of passage leading to a square section flooded shaft. The shaft appears to vary from about 5m to about 10m in depth, although it could be deeper. Ladders and old timbers can be seen in the water. It is possible to cross the shaft by crawling on some old timbers, but both branches of the subsequent fork quickly terminate.
ADIT 11 was the most southernmost adit surveyed. This soon enters a steeply inclined, narrow stope with a surface shaft above. Onwards a passage to the left exits to the river bank again. The main passage terminated just after a ninety degree bend where there is a shaft in the roof with a timber frame type structure supporting a pile of deads. The survey shows this point to be in the vicinity of a number of surface workings belonging to Bryn Cenhadon Mine.
Upon surfacing I followed the river upstream again and reached an area containing a large number of 10m deep shaft and stopes in a line parallel to the river. These were not entered on this occasion.
It is interesting to note that most of the passages trend from north to south. Despite the presence of the nearby mill, no stoping is present and not much ore appears to have been won from the Klondyke Adit - it appears to have been a largely unsuccessful prospecting venture trying to intercept the veins that had been exploited in the older Bryn Cenhadon mine further up the gorge. The levels further up the gorge - although smaller in extent have extensive stoping testifying to the ore removed.
The mill itself was built in the early 1900’s and processed ore from the Pandora Mine near Llyn Geirionydd. Ore was transported via tramway and then aerial ropeway to the mill. The Klondyke achieved a degree of notoriety just after the First World War as the scene of an elaborate fraud - See Below.
The ‘Klondyke’ Fraud It seems that during the period 1918 to 1921, the Klondyke was the scene of a massive fraud. The story is related in some detail in Mines of the Gwydyr Forest, but briefly what happened was this. A certain Joseph Aspinall took over the mine in 1918 and claimed to have discovered a huge vein of silver. What he did was to clean the passages of dirt, purchase 20 tons of powdered lead concentrate and glue it onto the walls giving the impression that the entire passage passed through a huge vein of silver. He then bought parties up from London to view the vein and procure an investment in the venture. A mass of miners were employed who actually did no work, let alone any mining. Whenever Aspinall turned up with a viewing party, a hoot of his car horn triggered the miners to busy themselves around the premises - some guarding the adit with cudgels, others running around the place like ants on an ant hill. By the time he was rumbled, he managed to secure £166,000 ! He got 22 months.'