Waste from C18th and C19th mining had covered the area completely hiding the signs of Bronze Age mining. When a car park was proposed in 1987, an underrground survery was needed to check on the stability of the ground.
As the layers of mining waste were removed, not only did it start to reveal open cast mining, but also the entrance to the Vivian Shaft which lead down into the C19th tunnels. When the archaeologists descended this, they discovered a labyrinth of Bronze Age workings and tools.
More and more of the surface workings were cleared and began to reveal the extent of the early open cast mines. More is still hidden beneath the later waste.
As the surface ore was exhausted, the Bronze Age miners began to tunnel underground, following the veins of ore and the openings to these underground workings were revealed. Archaeologists began to clear the tunnels and realised the extent of the workings. Over five miles of workings have already been cleared and explored, but it is thought this is less than half of those still waiting to be discovered.
The early tunnels were often narrow and twisting. Some were so small they could only have been worked by children.
Pathways, bridge and viewing platforms were built to give visitors access to the site. There is also a small shed with information about early smelting techniques.