The programmes

Grid reference: SH 442 903

Filmed 23-29 August 2003, first screened 11 July 2004

Ancient miners

For this programme, the Extreme Archaeology team headed to Parys Mountain, Anglesey, to investigate what was once the biggest copper mine in the world. As Victorian miners dug towards the rich ores, they reported finding mysterious existing tunnels. Who built them and when? Could they be evidence that people were mining copper on the mountain 4,000 years ago in the Bronze Age?

Today, two vast, disused mines with 20 kilometres of Victorian tunnels lie beneath a strange lunar landscape of spoilheaps. The mines were flooded with acidic water and largely inaccessible until recently, when they were drained for environmental reasons. Now, as the old timber supports dry out, there is a constant threat of collapse in the tunnels, many of which haven't been entered since the late 19th century.

Fear and determination

Undeterred, although distinctly edgy, the team set out to investigate underground. Fear and determination were evident in equal measure as the team members struggled to decide whether extracting the archaeological information justified the increasing risks they faced as they progressed further into the tunnels.

The problems ranged from pools of acidic water and weird chemical slime coating the roofs, walls and timbers, to 200-year-old rotting tunnel supports – the shoring in each tunnel had to be assessed for safety before the expedition progressed. Add in freezing temperatures, which imposed strict time limits on each expedition, and at times the archaeological goal of investigating and dating the ancient tunnels discovered in Victorian times seemed unachievable.

The fact that this goal was achieved (see below) has become all the more important in light of subsequent events. Several months after the programme was filmed, parts of the mine collapsed, sealing off much of the archaeology beyond many tons of rubble.

Expert opinion

Bronze Age mining expert David Jenkins describes the investigations into the two mines at Parys Mountain

Famous mines

Parys and Mona copper mines are famous, having dominated the world copper trade in the 1780s. Even then it was recognised that earlier mining had occurred on Parys Mountain; and in 1986 an ancient site was located and excavated by the Early Mines Research Group. Charcoal found in this excavation was dated to the Early Bronze Age (about 3,500 years ago). Permission was sought to re-open access to Parys mine, which had been sealed in 1980, and several Bronze Age sites were identified, with a further eight samples dating to the EBA.

Additional sites were known about and one was suspected from a 1740 map in the Mona mine, but buried below deep surface spoil. This had been inaccessible until earlier in 2003, when a major drainage operation had been carried out for safety reasons. This allowed access (some 70 metres or so down) to a partially-flooded joint drainage level connecting the Parys and Mona mines.

Parys Underground Group

The Extreme Archaeology team was invited by the Parys Underground Group (PUG) to join in the exploration of these newly exposed workings in the hope of investigating from underground the potential site buried beneath the surface spoil. Another known site was also offered for excavation in a remote part of the upper levels of Parys mine, together with other possibilities perched in the roof of a chamber above a deep, very acidic, pool.

Extreme Archaeology successfully excavated the known site in Parys mine and added a date, again from about 3,500 years ago, so extending the known range of these complex ancient workings. The sites above the pool were deemed too difficult to access, but the major project of exploring the surface site in Mona mine proved to be an exciting adventure down through the flooded drainage level and then up again through the recently drained workings.

Molephone communication

This exploration reached its planned destination and the team members were able to communicate by 'molephone' with the surface party. Subsequently, PUG found that they were only a few feet below the surface and could probably have communicated by voice alone! Indications of Bronze Age mining have also now been found there in the form of stone hammers or 'mauls'.

In addition to blazing the trail through Mona mine and providing a date for the workings, Extreme Archaeology, with its considerable technical resources, was also able to provide useful 3D images of these complex workings and overall made a valuable contribution to their study. Work on the prehistory of these extensive and remarkable mines will continue, including palaeo-environmental work at Coventry University and a geochemical survey to search for surface occupation sites.

Further information

For further information, visit the Parys Underground Group website at www.parysmountain.co.uk