Photos:: The royals visit the ‘Harry Potter’ set

The trio are said to have received a class in wand use.  (WPA Pool / Getty Images)

Pregnant Catherine and her husband, Prince William, Duke of Cambridge.  (WPA Pool / Getty Images)

The trio receive wands based on the magic wands in the books.  (Chris Jackson / Getty Images)

British author J.K. Rowling, who penned the best-selling “Harry Potter” series, meets with Catherine, Duchess of Cambridge.  (Chris Jackson / Getty Images)

Prince William is said to have shouted “Expelliarmus,” which in the J.K. Rowling books is the spell to disarm an opponent.  (Christ Jackson / AFP / Getty Images)

Britain’s Prince Harry, center, speaks with Warner Bros. U.K. President Josh Berger, left, as they leave the Warner Bros. Studios in Leavesden.  (Facundo Arrizabalaga / EPA)

The Warner Bros. Studios in Leavesden is said to be the first of its kind to be built in 70 years.  (WPA Pool / Getty Images)

Catherine, Duchess of Cambridge, and Prince William, Duke of Cambridge, pretend to challenge each other with their wands.  (WPA Pool / Getty Images)

Catherine, Duchess of Cambridge, speaks with children.  (WPA Pool / Getty Images)

Catherine, Duchess of Cambridge, and Prince William, Duke of Cambridge, take a tour of props used in some of the studio’s other films.  (WPA Pool / Getty Images)

The royals on the set used to depict Hogwarts School of Witchcraft and Wizardry’s Great Hall.  (Chris Jackson / Getty Images)

The royals and their guest take a stroll through the Great Hall.  (Chris Jackson / Associated Press)

The royals are said to have held a meeting with their charities in the Great Hall during their visit.  (Chris Jackson / Getty Images)

The Duchess of Cambridge looks at the costume for the character Hagrid in the “Harry Potter” films.  (Chris Jackson / Associated Press)

Prince Harry smiles as he stands on the set used to depict “The Burrow,” the house where the Weasley family lived in the “Harry Potter” books and films.  (Chris Jackson / AFP / Getty Images)

The Making of “Harry Potter” attraction opened last year but was inaugurated on April 26, 2013.  (Eamonn M. McCormack / Getty Images)

Catherine, Duchess of Cambridge, and Prince William, Duke of Cambridge, arrive at the inauguration.  (WPA Pool / Getty Images)

Prince William, Duke of Cambridge, makes a speech at the inauguration and thanked Warner Bros. for making the investment at Leavesden. “You were right to do so, and all three of us hope you have a long and prosperous stay here -- and please make another of the Dark Knight series,” he said.   (WPA Pool / Getty Images)

Prince William, Duke of Cambridge, holds a clapperboard at the inauguration.  (WPA Pool / Getty Images)

Prince William, Duke of Cambridge, sits on the Batpod, which was used in “The Dark Knight” films.  (WPA Pool / Getty Images)

Prince William and Prince Harry check out a Tumbler vehicle used in the Batman films.  (Chris Jackson / AFP / Getty Images)

The princes inspect the Tumbler.  (WPA Pool / Getty Images)

Prince Harry, left, and Prince William, Duke of Cambridge, inspect a Batman costume.  (Chris Jackson /Associated Press)

Catherine, the Duchess of Cambridge, watches her husband, Prince William, as he sits on the Batpod during the inauguration.  (Chris Jackson / Associated Press)