Illicit whisky distilling was big business. Estimates suggest that in 1787 alone, around 300,000 gallons was smuggled across the border into England.
By 1815 the law had been toughened, making it illegal to produce whisky in small stills, before finally in 1823 the Government decided to allow distilling in return for a licence fee.
This turned the production of whisky into a potentially profitable activity, and many former illicit distillers – notably George Smith, who founded Glenlivet – went “straight”.
Some illicit distillers went to elaborate lengths to conceal their activities.
In 1824, the author Samuel Morewood described the discovery of a hidden still in An Essay on the Inventions and Customs in the Use of Inebriating Liquors.
“Perceiving, however, some brambles loosely scattered about the place, he proceeded, to examine more minutely, and on their removal, discovered some loose sods, under which was found a trap door leading to a small cavern, at the bottom of which was a complete distillery at full work, supplied by a subterranean stream, and the smoke conveyed from it through the windings of a tube that was made to communicate with the funnel of the chimney of the distillers’ dwelling-house, situated at a considerable distance,” he wrote.
Despite the key part that whisky has played in Scotland’s social history, Mr Alexander says the network of illicit stills has been neglected by archaeologists until recently, partly because they are not very old.
He adds: “There’s not a lot of documentary sources about them – you didn’t write these things down because it’d be easier to get caught.
“So there’s not a lot of good written evidence about them and once they get forgotten, they get forgotten about quite quickly.
“There’s always stories about how some local guy hid things up in the hills, but there’s very little specific about places, actual places on the ground.
“That’s really what we’re trying to do, find the sort of material remains of the actual locations.”
The NTS has been researching 30 illicit stills on its own properties across Scotland, and has also been excavating the original site of George Smith’s Glenlivet distillery in Moray, with more work planned for 2022.
Mr Alexander says he was “keen to hear” about other potential illicit still sites and is encouraging members of the public to report anything they stumble across.
This can be done via Canmore, the online catalogue of archaeological sites run by Historic Environment Scotland, where people can check if their discovery has already been found.