On the south side of Loch Tay there is a disused copper mine which was started by the Marquis of Breadalbane with German mining engineers. The mine is now in ruins and the roof has collapsed in one place to create a cavern.
Below the mine entrance there is a large spoil heap and here you can find the typical copper bearing minerals - Azurite (blue), Malachite (green) and Chalcopyrite (brassy coloured).
In places the walls of the mine sparkle with pyrite (fool's gold).
If you descend the steep hillside from the mine to the shore of Loch Tay you will find some ruins of the mine buildings and possible some artificial obsidian (glass) left behind from the smelting activities.
Evidently the mine became uneconomic and was abandoned.