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Creepy castle?

Prince William and Duchess Kate's London residence, Kensington Palace, is open for ghost tours, the Daily Mirror reports. According to the site, Kensington will be open for four nights on Halloween weekend (Oct. 28 to 31) for tours.

According to USA Today, the Eerie Evening Tours of the Enchated Place will last an hour and a half each an cost about $33 per person.

The palace is said to be haunted by the spirit of Queen Mary, William's great-grandmother.