Not any old rubbish: Edinburgh’s Mound was built to order from rubble, pipes and oyster shells

For more than 200 years, the creation of Edinburgh’s famous Mound has remained something of a mystery.

Built on the boggy bed of a drained loch in the late 18th and early 19th century, the artificial mound connected the city’s medieval Old Town with the burgeoning prosperity of the New Town, transforming the Scottish capital.

The origins are said to have been laid in the 1770s by a tartan salesman called George Boyd, who – seeking a shortcut across the swampy ground to the elegant new buildings rising up next to it – put down stepping stones and planks, creating a path known as Geordie Boyd’s Mud Brig.

Historians previously thought Old Town residents then built up the path in an ad hoc manner over 50 years, by dumping their household waste there, along with cartloads of earth and rubble from New Town construction sites. Eventually, it was thought, this huge rubbish tip grew to become the Mound.

Now, new evidence suggests the town council actively regulated and oversaw the remarkable construction of the Mound from local rubbish.

As the land is now a world heritage site, with Victorian railway tunnels underneath and category A-listed buildings above, archeologists have had little opportunity to investigate the accuracy of its oft-repeated origin story.

However, the Observer can reveal that a rare archeological study commissioned during excavation works by the National Galleries of Scotland, which opened a new site on the Mound last year, found very little household rubbish, food or organic waste present.

Instead, the study by Addyman Archaeology indicates that the town council systematically supervised the dumping of certain waste – ceramics, oyster shells, clay pipes, glass, tiles, bricks and other demolition debris – into well-ordered deposits that were channelled into carefully managed zones and placed in defined locations.

“It would have been in the council’s interests to ensure the rubbish laid down was clean waste – so non-organic matter,” said Dr Patricia Allerston, curator at National Galleries of Scotland. “It must have been quite an operation. So it must have been regulated in some way.”

Instead of refuse being dumped on the land in an indiscriminate manner, the new findings suggest the depositing of waste on the mound was a highly controlled process, with designated cart routes for the particular types of materials that were permitted to be dumped.

Both 17th and 18th century bricks have been found, suggesting some of the rubble came from construction sites in the Old Town where buildings were being demolished.

The revelations shed light on the history of Edinburgh, indicating that as the city grew, forward-thinking town planners took pains to ensure residents and builders repurposed and recycled their waste in the most efficient way. “The surprise of this study was that it showed civic organisation, perhaps earlier in this area than was anticipated,” said Allerston.

Art historians have been able to reinterpret contemporary paintings and drawings of the Mound, which are on display in the new galleries built upon it, in the light of the new discoveries.

For example, one painting, Edinburgh Castle and the Nor’ Loch, by Alexander Nasmyth, depicts a man tipping a cart into a loch by the castle and another man standing nearby with a spade. Two other men in smart clothes and hats stand in the foreground, near the cart: one is surveying the scene and the other is holding up a piece of paper. “I went back to the picture and thought: wow,” said Allerston.

She had always assumed the man holding the paper was drawing the castle. “But it makes you think again: who are these people and what are they doing there? Because they do look like officials.”

The painting was traditionally perceived to be a nostalgic view of the castle, because Nor’ Loch had been drained and did not exist when Nasmyth was painting it. But now, Allerston thinks the artist, who was the son of a builder’s merchant, was also excited about the changes that were happening to the city and wanted to paint this tension.

She said: “It’s not just the nostalgic reaction of somebody looking back and feeling a bit sad about what’s happened to the city. He’s really interested in the city as a dynamic, changing place … it shows the official process that was transforming the city.”