Stars surprise fans on 'Back to Hogwarts' day

Smile for a selfie! Jude Law and Eddie Redmayne surprise fans.

Some lucky Wizarding World fans from around the country had a very special treat this weekend.

They headed to Platform 9 ¾ at London's King's Cross Station in their very own Knight Bus, inspired by the mode of transport from Harry Potter and the Prisoner of Azkaban.

The bus had beds covered in Harry Potter bedsheets and travellers got to watch Fantastic Beasts and Where to Find Them during their journey.

When they got to the station they joined hundreds of fans for the 11am countdown to the Hogwarts Express' departure and were surprised by Fantastic Beasts: The Crimes of Grindelwald actors, Eddie Redmayne and Jude Law.

There's no space for trains with all these fans!

Finally, if that wasn't enough of a treat the fans were taken on a tour around Warner Bros. Studios Tour London - The Making of Harry Potter.

Actors Jude Law and Eddie Redmayne heading to the platform.