Conspiracy theorists see them everywhere, from the paintings of Da Vinci to the humble dollar bill.

Real or imagined, the symbols of Freemasonry through the ages have beguiled and tantalised. Now their biggest secret may have been exposed in the heart of Scotland's biggest city.

Research has suggested Glasgow Necropolis is a giant masonic symbol, fully 37 acres of landscaped metaphor.

Historian Ronnie Scott has unearthed previously unseen patterns in the design of the early 19th-century cemetery.

His theory, to be formally unveiled at the world's first conference on the history of Freemasonry in Edinburgh later this month, would turn upside down the history of one of Scotland's best-known landmarks. It would also make the Necropolis one of the biggest masonic sites on the planet.

"The more I looked, the more I saw," Mr Scott explained yesterday after years of painstaking study at Glasgow University. "I began to see a pattern emerge and the Necropolis began to look like a very large and very solid representation of masonic ideals and symbolism.

"The Necropolis is clearly a symbolic landscape and my research indicates that we should start to think of it as a freemasonic landscape, one that has been planned and modelled as the moral teachings of the Craft, made solid and very visible. Hidden in plain sight, you could say."

The Necropolis opened in 1833 and for more than a century was the only place in which the great and the good of Glasgow would be seen dead. All the main players in its planning were Freemasons. So too were many of the men interred in its many ornate crypts and graves, often structures emblazoned with symbols of the craft.

The monument to Walter Macfarlane, Glasgow's Victorian king of cast iron, looks like a Royal Arch, the emblem of the fourth degree of Freemasonry. Many others feature Egyptian architecture, which inspired so much of the iconography of the masons, who, some legends have it, keep the secrets of the pyramids. Indeed, the Necropolis was inspired by Pere Lachaise, the Paris graveyard that was itself designed by a Freemason.

But it was the design of the cemetery that gave Mr Scott, who is not a mason, his greatest clue. "Just as a Freemason's career progresses from the west to the east, and from darkness to light, so is the Necropolis laid out," he said. Those entering the graveyard pass over a bridge, by an arch, through two pillars and up a hill, on a journey from west to east.

Mr Scott's theories are causing excitement among scholars of Freemasonry. More than 230 professors from across Europe, America and Asia will gather in Edinburgh to discuss his findings and other research.

Among them will be Robert Cooper, curator of the Grand Lodge of Scotland. He said: "There are several cemeteries in Scotland where there are graves with masonic symbols, for example, Robert Burns's in Dumfries, which is very masonic in its design."

Mr Scott, who recently published a history of the Necropolis called Death by Design, is not the only academic set to explore the mysterious world of symbolism at the Edinburgh get-together.

"This conference is very much Freemasonry coming home," Mr Cooper said.

Freemasonry is widely believed to have firm Scottish roots. The earliest surviving minutes of a masonic lodge date from Edinburgh in 1598. The craft grew out of a professional guild for the men who built medieval cathedrals into an international organisation that has inspired countless conspiracies. The Necropolis would be far from the only landmark in the city with masonic symbolism. Mr Scott cites emblems on a tenement next to the Buttery restaurant in Argyle Street and a masonic temple in West Regent Street.

The building best known for its masonic influences in Scotland is Rosslyn Chapel, thanks to Dan Brown's Da Vinci Code. Mr Cooper, however, stresses Rosslyn is a Catholic Church, not a masonic building. The Necropolis, some are already speculating, could become an even more important site of pilgrimage for the world's six million Freemasons.

Building a theory THE NECROPOLIS The graveyard was opened in 1833 by a group of men from the Merchants' House of Glasgow, most of whom are understood to have been masons. Its location and layout mirrors the masonic journey "from darkness to light". Those entering the cemetery do so across a bridge, through two pillars and by an arch before they climb a hill. All, as in the masonic journey, from west to east. There are clear masonic emblems on graves and crypts. The Necropolis has long played on the imaginations of Glaswegians, often in ways far more sinister than the worst fears of masonic conspiracies. The cemetery features prominently in Alasdair Gray's 1981 novel Lanark. The eponymous hero of the book is swallowed by a huge mouth which opens in the ground of the city graveyard and leads him into the hellish subterranean world of the Institute, where the population lives on human flesh.

The freemasons The first recorded meetings of Freemasons were in Edinburgh, in 1598. There are now six million Freemasons worldwide, 70,000 of them in Scotland. Notable Scottish masons have included Robert Burns; Sir Walter Scott; Sir Harry Lauder; Jimmy Shand; and Jock Stein. Worldwide masonry has attracted everybody from great statesmen to artists. Mozart was a mason. So was Winston Churchill, George Washington, John Steinbeck and even the 20th-century socialist firebrand Manny Shinwell. The organisation is split into numbered lodges. Members used to discover which lodge a fellow mason was in by asking "how old your granny is". The answer wasn't an age, but a lodge number.