Warner Bros' Harry Potter studio tour outside London, UK has opened its biggest expansion to date, with the launch of the iconic Gringotts Wizarding Bank.

Officially opening on 6 April, the 16,500sq ft expansion has been designed and built by many of the original crew members who worked on the hugely successful magical film series – including Oscar and BAFTA-winning production designer Stuart Craig, construction manager Paul Hayes and head propmaker Pierre Bohanna.

The Gringotts bank – run by goblins – features heavily in the Harry Potter universe, especially on film.

The permanent attraction will allow visitors to walk through the bank, the Lestrange vault, a gallery of goblins and more.

Lined by towering marble pillars, the grand banking hall features the goblin tellers’ desks – complete with inkwells, quills, ledgers and piles of galleons, sickles and knuts.

Visitors will discover the costumes and prosthetics belonging to characters such as Bogrod, Griphook and other goblin bankers. Each prosthetic mask worn by the actors playing the goblins took weeks to create, with every hair individually inserted and veins painstakingly painted by hand.

Once through the banking hall of Gringotts, visitors will enter the depths of the Lestrange Vault used to store the treasures of Bellatrix Lestrange including the Sword of Gryffindor and Helga Hufflepuff’s Cup, one of Voldemort’s many Horcruxes.

During filming 38,000 pieces of rubberised treasure were created the for the Lestrange vault including 7,014 Hufflepuff Cups. Here, visitors are offered a photo opportunity allowing them to step inside the Lestrange vault and surround themselves with treasure.

"There are hidden gems everywhere and secrets to find," said special effects supervisor John Richardson, describing the new addition.

"The extraordinary thing about it is that the children love it – because it's magical – and the grown-ups all love it because many of them grew up with Harry Potter. But at the same time, people don't know how movies are made and what goes into making movies, so they can learn about all the tricks of the trade and find out how the magic is created."

In addition to the Gringotts Wizarding Bank expansion, Warner Bros. Studio Tour London will unveil an all-new 17,000sq ft lobby and café on 6 April. The new café will serve food and drink inspired by the Wizarding World and can seat up to 500 people.

Warner Bros. Studio Tour London – The Making of Harry Potter first opened its doors on in March 2012.