STOCKHOLM -- One of the Swedish royal family’s palaces is haunted - but the phantoms are “pretty friendly,” says Queen Silvia.

“There are ghosts, many,” Silvia says of Drottningholm Palace in a documentary to be aired Thursday on public television channel SVT. “You feel you get a little excited” when talking about them, she adds, smilingly.

Asked whether Sweden’s longest-serving queen had experienced the ghosts herself, she replied “of course. But they are friendly.”

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Located on an island in Stockholm’s archipelago, the royals’ private residence was originally built in the late 16th century. Drottningholm Palace is listed on the UNESCO world heritage list, and has been the royal family’s residence since 1981.

King Carl Gustav’s boat is moored outside Drottningholm Castle during preparations for Princess Leonore’s royal christening on June 7, 2014, in Drottningholm, Sweden. Torsten Laursen/Getty Images

Silvia, born in Germany as Silvia Renate Sommerlath, is married to King Carl XVI Gustaf, Sweden’s ceremonial head of state. The pair met at the 1972 Olympic Games in Munich, and wed in 1976.

The royal family, whose role is ceremonial, is hugely popular in Sweden and the monarchy enjoys widespread support despite the egalitarianism that otherwise characterizes society in the Nordic country.