According to a recent post by George R. R. Martin, the Magheramorne quarry in Northern Ireland will be the location of the Castle Black set.
The LARNE TIMES broke the story a “massive castle” being build in an old quarry near Magheramorne for HBO’s GAME OF THRONES. The quarry is about forty minutes north of Belfast, near the town of Larne.
I can confirm that, more or less. The set being built at Magheramorne will be our Castle Black. Not actually THAT massive a castle — much of Castle Black will be created in post with CGI — but it will come complete with a fully operable winch elevator, David and Dan tell me.
Winter Is Coming: A fully operable winch elevator? That’s pretty cool. Will be interesting to see that in action. George also mentions not to try and visit the site due to safety reasons. Probably sound advice, last thing we need is some over-zealous fans getting crushed by a falling boulder or something.