Along one wall of the machine hall at Cruachan is a mural of inlaid woods, by artist Elizabeth Falconer, which depicts the legend of Cruachan.
The intricate mural tells the tale of the Cailleach Bheur, or Old Hag of the Ridges, who was the guardian of a fountain that welled up from the peak of Ben Cruachan.
Her duty was to cover the spring with a slab of stone at sundown and lift away the rock at dawn. One evening she fell asleep and the well overflowed.
The water, rushing down the mountainside, burst open a new outlet to the sea through the Pass of Brander. By the time the Cailleach awoke, the water had flooded the wide strath below and drowned all the people and their cattle.
Legend says this is how the River Awe and Loch Awe were formed. The Cailleach was turned to stone as punishment for her negligence and sits to this day, high on the mountain, above the Pass of Brander.
Cruahan power station was constructed between 1959 and 1965. It was the first reversible pump storage hydro system to be built in the world. Cruachan was the brainchild of Sir Edward McColl who sadly died before the power station was opened.
The first plant items to be installed in the cavern were the turbine casings, which were mounted at the lower levels within the cavern.
A 275,000V transmission line was constructed to carry the power from the top of the cable shaft just in front of the dam, to dalnally substation, 5 miles east of Cruachan, and then on to Windyhill, north of Glasgow. This line passes through rough terrain, and at its highest reaches 1800 feet (549 metres).
The power station was officially opened by the Queen on 15th October 1965. Two of the machines were completed at this time, with the remaining two coming into service in 1966 and 1967.
Cruachan, when built, was the highest head reversible pump/turbine power station in the world. A lot of time was spent at the design stage, optimising all aspects of construction and operation. Many working models were built of the turbines and work tests were carried out on complete alternators before shipping to site. Because of the limitations of local roads and the size of the access tunnel, all the equipment had to be broken down into manageable loads for transportation.