Call it magical timing.

Normally I wouldn't approve. But she's a huge Harry Potter fan, and only lives 15 kilometres from the world-class Harry Potter experience that some stupid muggle ridiculously named "Warner Bros Studio Tour London". But she's never been.

Amazingly, it is almost 20 years since J.K. Rowling's Harry Potter and the Philosopher's Stone was released on June 26, 1997.

Indeed, four years have passed since the final movie, Deathly Hallows Part 2, opened. The eight films have grossed more than $10 billion, making Harry Potter the second highest-grossing film series in history after the Marvel Comics superheroes franchise.

And Harry Potter is as popular as ever with children, which explains why we need to prebook this tour several days in advance.

The name of the attraction is misleading because it's not in London. The working studio complex is an 80-hectare former World War II aerodrome and airplane factory in Leavesden, Hertfordshire – about 30 kilometres north-west of central London.

It's one of the few remaining places in the United Kingdom where large scale movies can be made. Apart from the Harry Potter franchise, other movies shot here include GoldenEye, the later Star Wars films, The Dark Knight,  Kingsman – The Secret Service, and The Man from U.N.C.L.E.

But since 2012, Leavesden has mainly been known as home to what the British call Harry Potter World, although The Wizarding World of Harry Potter is in Orlando, Florida.

Only 5000 fans are allowed to visit the British version per day, each allocated a specific tour time. But this makes the experience really rich, allowing you plenty of time to explore each of the fascinating exhibits without feeling too crowded.

The tour begins as soon as the guide opens the vast doors to The Great Hall at Hogwarts. This was one of the first sets to be built and has been used in each of the films, seating 400 children at a time split into the four Hogwarts houses: Gryffindor, Ravenclaw, Slytherin and Hufflepuff.

It's impossible to overestimate the "wow factor" as children see the Great Hall for the first time. There are also costumes worn by the actors playing most of the teachers – including Dumbledore, Snape, Professor McGonagall and Hagrid.

Even if you're not a Potter fan, this is a fascinating place to come if you love movies generally. Here you will learn so much about the artifice, ingenuity, science and craftsmanship which goes into movie production.

Take Dumbledore's fabulous office, first seen in The Goblet of Fire. That library of books may look impressive, but most are copies of the London telephone directory covered in leather.

Or the triple-decker Knight Bus from Prisoner of Azkaban. Like most people, I'd assumed the Knight Bus was a CGI creation, but it was bolted together by the special effects team from two iconic Routemaster buses.

You can walk through the Knightbus on the back lot, before you pose for a photo outside 4 Privet Drive, home of the dreadful Dursley family, where both the book and movie series began.

Diagon Alley is a must-see too. The wizarding version of HIgh Street Australia includes Ollivanders wand shop where Harry chose his wand (or did it choose him?). It took the film team six months to build but it looks as if it has been there at least since Dickens published A Christmas Carol.

If I have one tip, it's this. Pay extra for the "digital guide", narrated by Tom Felton, the actor who played Draco Malfoy in the film series. It's brilliant: an industry standard of what an audio guide should be – informative, inclusive, and as concise or expansive as you want it to be.

My niece and eldest son also used their spending money to have a first-hand experience of green screen technology. In other words, they rode a broomstick while pretending to play quidditch.

Not to worry. While we are waiting for them, my younger son and I tuck into a tankard of frothing Butterbeer (it's ghastly, a liquid version of butterscotch) and a packet of Bertie Bott's Every Flavour Beans (the Vomit flavour is surprisingly tasty).

Just one final warning to parents. Save a bit of money for the gift shop. Normally I can drag a whole classroom of kids out of a gift shop as smoothly as a TV homicide detective says: "Move on people, Nothing to see here."

But this stuff is "collectable". My niece and sons have to drag me out.

But at least I have my own wand now. Whose?

Snape's, of course! Now go to bed.

TRIP NOTES

MORE INFORMATION

wbstudiotour.co.uk

GETTING THERE

Sadly, there's no Platform Nine and Three-Quarters if you are travelling to Leavesden by rail. You don't even depart from King's Cross.

Instead, head to Euston Station, catch the train to Watford Junction and take the £2 each-way shuttle bus.

If you're driving, Leavesden is four kilometres from both the M1 and M25 motorways.

Steve Meacham travelled at his own expense.