'Game of Thrones' castle can be yours -- but bundle up

'Game of Thrones' fans: If you've ever wanted to own a Westeros castle, now's your chance. The castle that was used for the exteriors of House Tully's "Riverrun" in season three is up for sale.

Officially, it's known as "Gosford Castle." It was built in the mid-1800's by the 2nd Earl of Gosford, Archibald Acheson. During World War II, the property was commandeered and used to house troops and even prisoner-of-war camps.

It's actually only part of the Northern Ireland castle that's for sale. According to the listing, it's been partially developed and could house up to six apartments.

The official listing boasts 15 bedrooms and 10 bathrooms, and it comes with a starting price tag of a half-million pounds - which is a little more than $600,000.

One big catch: There's no heat. So you might have to save room in your budget for some GOT-style costumes.

LINK: See the full listing and photos