IT is 25 years since the first Harry Potter novel was published, with the boy wizard's adventures bewitching and beguiling generations of readers from that moment on.

Now the Edinburgh-based author has revealed the inspiration behind some of the key locations in her series of books, which have sold more than 500 million sales mark back in 2018.

Ms Rowling told her 14 million Twitter followers that despite a firmly held fan belief that Edinburgh's Victoria Street was the inspiration for Diagon Alley - the cobblestoned, shop-lined wizarding thoroughfare where Harry and his Hogwarts friends stock up on their supplies, from Owls to wands - the alley was purely fictional.

She said: "No real street inspired Diagon Alley, I'm afraid. It came out of my head! I've never seen 99 per cent of the places that claim to be the inspiration and I'd never seen Victoria Street when I created DA (I have since, obviously, as it's in Edinburgh, where I live)".

The mother-of-three did, however, reveal that aside from real-life places such as King's Cross that feature in the novels, one "wizarding world location" does indeed come from real life.

She added: "I feel bad for the tourist boards saying it, but all (wizarding world) locations in Potter are entirely imaginary bar one - which is the most boring. It was only when I'd written the first three books that I realised I'd given 4 Privet Drive exactly the same layout as the second house I lived in as a child (which did have a cupboard under the stairs). Dull but true: I haven't even been to many of the cities containing the self-proclaimed 'real' Diagon Alleys!"

And when one of her followers, Shivan Davis, tweeted that a guide on a walking tour of Edinburgh claimed that many of the character names Ms Rowling uses come from a particular graveyard, the author revealed she was well aware of this suggestion, thanks to the efforts of one of her children.

She revealed: "Unbeknownst to me, one of my children was at a loose end one afternoon and went on one of those Potter walking tours with their best mate for a laugh. They came home with a ton of information that was news to me."

The Ink Black Heart, Ms Rowling's latest Cormoran Strike detective novel, written under the name Robert Galbraith, comes out in August.