There is little obviously magical about Wyedean school in Gloucestershire.
But staff claim that the comprehensive, founded in 1973, is the model for the centuries-old towering spires of Hogwarts, the school attended by Harry Potter.
Harry's author, JK Rowling, was a pupil at Wyedean in the late 1970s. And staff believe its influence has stayed with her.
John Claydon, headteacher, said: "This school is her secondary experience.
When JK Rowling was here, she observed very precisely what was going on.
There is no doubt that elements of our school are in the books."
He cites the house structure at Hogwarts, also an integral element of Wyedean: "The competition between houses, and the way sport is used for that, is a feature of our school. Both schools also use sport as a character-building exercise."
For Mike Thompson, a science teacher at the school for 30 years, the similarities between Hogwarts and the Wyedean of the 1970s are more explicit. "Professor Snape, the potions master, is undoubtedly John Nettleship, the head of chemistry," he said.
"He had a big nose, and long, dark hair, just like Alan Rickman in the film. He could be quite strict. He wasn't the most popular guy."
Similarly, he says, Madame Maxime, the giantess teacher visiting Hogwarts from France, has origins in the Wyedean staffroom: "The French teacher we had here was tall, with a big personality."
While Ken Smith, founding head of Wyedean, was clean-shaven, Mr Thompson believes that he shared certain qualities with Professor Dumbledore, the long-bearded Hogwarts head notable for his absent-minded wisdom.
"He was well-spoken and very well-read," he said.
The young Joanne Rowling was a high-achiever. In her final year at Wyedean, she was appointed head girl. But teachers at the school failed to spot any nascent ability for creating worldwide phenomena.
"Jo was quiet and worked hard," said Mr Thompson. "She didn't stand out as being exceptional."