Bwlchgwyn Mine

Overview

A lead mine on the high ground at Ystumtuen above the Rheidol gorge, east of Aberystwyth, worked from at least 1735 and often run together with its immediate neighbours Ystumtuen, Penrhiw and Llwynteifi. The ground belonged to the Nanteos estate, which is why the mine is also called Nanteos. Lewis Morris looked at it in the 1740s and thought it had the prospect of a great work, worked with hardly any powder. By the late nineteenth century all four mines were connected underground and drained through the same adits to the Rheidol, where their water is still a problem today.

History

Ystumtuen lies on a craggy block of upland between the steep Rheidol valley and open moorland, and in the medieval period sat between Strata Florida's grange of Cwmystwyth and Cwm-hir's at Nantyrarian. It later became a possession of the Nanteos estate: a document of 1690 lists seven farms there as belonging to Nanteos, and it is that ownership rather than any connection with the mansion near Aberystwyth that gives Bwlchgwyn its alternative name of Nanteos Mine. The area was an important mining district working from at least the early eighteenth century, Bwlchgwyn among the mines of Ystumtuen, Tynyfron, Penrhiw and Llwynteifi. Bwlchgwyn itself is recorded as worked from 1735. Lewis Morris, whose 1744 map of the area shows both the farms and some of the mines, wrote that it 'hath the Prospect of a Great Work, having a fine range of Ground to the Eastward, and is wrought with very Small Expense, there being hardly any powder used', the vein in the bottoms twelve to eighteen inches wide with ore found in soughs in good quantities, mixed with a kind of dirty clay. He also noted ancient working on a north lode which the landowner, Powell of Nanteos, was driving an adit to reach. Through the following centuries the mines of the group were developed and worked intermittently under numerous owners and in various combinations. By the late nineteenth century Ystumtuen, Penrhiw, Bwlchgwyn and Llwynteifi were all connected underground, so that the whole complex drained to the River Rheidol through two adits, numbers 6 and 9, which emerge on the steep valley slopes at Cwm Rheidol. There a mill dressed the ore before an aerial ropeway carried it across the valley to the Vale of Rheidol Railway and on to Aberystwyth. The population of Ystumtuen grew through the first half of the nineteenth century with the lead, the hamlet acquiring a chapel and a school, and fell away again as the industry died in the early twentieth century.

Geology

The mine works the Central Wales orefield, lead and zinc in steeply dipping veins in Lower Palaeozoic mudstones and grits. Lewis Morris described the vein in the bottoms as twelve to eighteen inches wide, the ore lying in soughs in good quantity mixed with a dirty clay, and recorded a separate north lode carrying ancient workings. The Ystumtuen lode crosses the Rheidol east of the mine.

Geological setting: Veins and Lodes (well documented example)

Workings

Bwlchgwyn stands at about 290 m on the upland above the Rheidol, with a crusher house and wheelpit below the engine shaft. Its workings were driven and drained in common with its neighbours: by the late nineteenth century the four mines of the group were connected underground and the whole complex drained through adits No. 6 and No. 9 low on the valley side at Cwm Rheidol, where the dressing mill and the aerial ropeway to the railway stood.

Closure

The lead industry of the district collapsed in the opening decades of the twentieth century, and migration from Ystumtuen followed: sixty houses were occupied in 1907, and thirty-six by 1988, a third of them holiday homes.

What remains

The site is on private land. The crusher house and the wheelpit below the engine shaft survive. The consequences of the workings have not gone away: the underground complex still drains through adits No. 6 and No. 9, both highly acidic and heavily laden with zinc, lead and cadmium, and those discharges are enough on their own to keep the River Rheidol failing water-quality standards for zinc and cadmium for eighteen kilometres down to the tidal limit. Natural Resources Wales diverted a stream away from a shaft in 2007, drained down adit No. 9 in 2008 to reduce the risk of a catastrophic minewater blow-out of the kind that has happened periodically in the past, and in 2009 piped both adit discharges into a pilot vertical flow pond. Running since September 2010 on a mixture of farm manure, woodchip, digested sewage sludge and cockle shells, it has removed up to 99 per cent of the zinc, lead and cadmium, though zinc removal fluctuates and averages around 60 per cent.

Related mines

• Penrhiw Mine — Bwlchgwyn lies immediately west of Penrhiw and the two were worked together for much of the nineteenth century; by its end their workings were connected underground and drained through the same adits.
• Ystumtuen Mine — One of the four mines of the Ystumtuen group, connected underground with Ystumtuen by the late nineteenth century and draining with it to the Rheidol through adits No. 6 and No. 9.

Nearby mines

• Penrhiw Mine — 0.6 km W
• Ystumtuen Mine — 0.7 km W
• Llywernog Mine — 2.3 km N
• Bwa-Drain Mine — 3.6 km NW
• Cwm Rheidol Mine — 4.2 km W

Straight-line distance, within 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.

• Bwlchgwyn is recorded as worked from 1735, within a district that was mining from at least the early eighteenth century. ^1,2
• Lewis Morris wrote in the 1740s that the mine had the prospect of a great work with a fine range of ground eastward, worked at very small expense with hardly any powder used, the vein in the bottoms twelve to eighteen inches wide. ²
• By the late nineteenth century Ystumtuen, Penrhiw, Bwlchgwyn and Llwynteifi were all connected underground and drained to the River Rheidol through adits No. 6 and No. 9. ³
• The two adits still discharge highly acidic water carrying elevated zinc, lead and cadmium, enough to keep the Rheidol failing Water Framework Directive standards for zinc and cadmium for 18 km to its tidal limit. ³
• A pilot vertical flow pond treating the two adit discharges has been running since September 2010 and has achieved removal rates of up to 99 per cent for zinc, lead and cadmium, though zinc removal fluctuates and averages about 60 per cent. ³

Photographs & further reading

Sources

1. (primary) Ystumtuen — Historic Landscape Character Area, Upland Ceredigion — Heneb: The Trust for Welsh Archaeology
2. (observational) Bwlch Gwyn — Buddlepit Mine Database
3. (primary) Abandoned Mine Case Study: Cwm Rheidol Lead & Zinc Mine, June 2016 — Natural Resources Wales

Record created: 9 September 2026 · Last researched: 9 September 2026