Harry Potter fans are clamoring to book a limited number of rooms at a central London hotel that were decorated based on the popular J.K. Rowling books.

The hotel rooms -- also called the Wizard Chambers -- have been decked out with potion bottles, cauldrons and "unexpected wizardly details," according to the Georgian House hotel website. "They have a gothic feel, very true to the spirit of Hogwarts."

Muggle fans, however, might have to wait to book a room. The hotel's website has been crashing after unexpectedly high customer demand, and calls are taking a long time to go through. A spokesperson at the front desk told CNNMoney the phones have been ringing off the hook.

The hotel is booking rooms into December 2015.

Georgian House hotel has been offering a couple Harry Potter-themed rooms for a year. But demand in recent days skyrocketed after some local ads led to a storm of media coverage.

The Harry Potter-themed holiday doesn't come cheap. One night's stay for two costs £209 ($340) and the price shoots up to £363 ($585) if you include breakfast, a special "Muggle Walking Tour" and tickets to a Warner Brothers Studio Tour that showcases the making of Harry Potter movies.

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The final novel in the Harry Potter series was published back in 2007, but the popularity of the boy wizard persists.

In July, Universal Studios Japan unveiled its long-awaited theme park -- the Wizarding World of Harry Potter.

It's the second Potter-focused theme park from Universal -- the original opened in Florida in 2010.

Universal Studios Hollywood is said to be getting its own version in 2016.

To keep fans interested, author J.K. Rowling also recently posted a short story on her "Pottermore" website, which gives a glimpse into the life of a 30-something Potter.