The students got the chance to explore famous sets from the films - including Diagon Alley.
They also created photographs of themselves riding in the magical flying car from "Harry Potter and the Chamber of Secrets".
'Magical,' 'mid-blowing' and 'the best first week ever' - not what you'd expect to hear from even the most keen Year 7 students. But for pupils at Queens' School in Watford it really was like none other. The children had their first assembly of secondary school on the set of Harry Potter.
Two hundred had the chance to sit at the long banquet tables where cast members including Daniel Radcliffe, Emma Watson and Rupert Grint shot many of their famous scenes.
Students have been reflecting on their most exciting start of term yet - following in the footsteps of Harry Potter. Year 7 pupils from Queens' School in Watford had their first assembly of the school year in the Hogwarts Great Hall, on the set of Harry Potter.
For one group of Year 7 pupils, going back to school after the long Summer holiday is an occasion they'll never forget.Read the full story ›
The Queens' School in Watford will have their first assembly of the school year within the iconic Harry Potter film Great Hall set at Warner Bros. Studio Tour in London, marking the first time that a school assembly has taken place here since filming.
The year 7 pupils are being given the once-in-a-lifetime chance to sit at the long banquet tables in the Great Hall where cast members including Daniel Radcliffe, Emma Watson and Rupert Grint shot many scenes.
Also going under the hammer at the First Editions, Second Thoughts auction last night was a copy of Roald Dahl's Matilda, with new illustrations by Quentin Blake, which sold for £30,000 - the second highest sale of the evening.
The auction saw lots from 50 celebrated authors who had annotated, commented on or illustrated a first edition copy of one of their works.
Other highlights included Kazuo Ishiguro's The Remains of the Day, which sold for #18,000, Julian Barnes' Metroland, which went for #14,000 and Alan Bennett's The Uncommon Reader, which fetched #11,000.
The one-of-a-kind copy of Harry Potter And The Philosopher's Stone contains revealing commentary and 22 of the author's own original illustrations. The book, which was published in 1997 and went on to bring Rowling worldwide fame, was sold to a telephone bidder at Sotheby's in central London.
A first edition of the first Harry Potter book, personally annotated by JK Rowling, has sold for £150,000 at auction.
If you want to know what JK Rowling thought about the book that introduced Harry Potter to the world, now is your chance.
A first edition of "Harry Potter and the Philosopher's Stone" is being auctioned, complete with the author's scribbled note that it 'changed her life for ever'.
It is one of more than 50 books containing notes by their authors, which are up for auction tomorrow at Sotheby's in London.
The sale called "First Editions, Second Thoughts" is raising money for the writers' association English Pen.