Here's the latest post from the Making of Game of Thrones blog, which talks about the work going into a huge battle scene for season 4:
Two years ago in a quarry just north of Belfast, the Battle of Blackwater came to life under the keen eye of director Neil Marshall. It was not an easy shoot, requiring nearly a month of night shoots in the unforgiving October weather. The red mud was so churned up by the trucks and the feet of the marauding hordes of extras and crew, that by the end, it was no longer possible to drive anything but the sturdiest of vehicles down to the castle set. Carrying kit out became a challenge of endurance.
Two years and two seasons on, we have returned to a location not far from the first and Neil is back at the helm once more. It's still several weeks of night shoots, and being Belfast, there is still rain, but this time the fight Neil is navigating is not anywhere on the water. The planning of this battle has been taking place for months but unlike any other episode of Season 4, Neil's will be filmed in a very concentrated burst. In fact, for many on the show – including most of the cast and the other directors, their work was complete before filming on this episode had even begun.
Throughout our shooting schedule, our crew and specialist departments are on their toes, but perhaps never more so than this season. This episode has kept the teams in stunts, armoury, prosthetics, SFX and VFX particularly busy, with camera tests and stunt rehearsals happening for several weeks beforehand.
As always, I can't give too much away, but a little hint won't hurt: Although this battle will not be laden with wildfire, I can say you've never seen an army like this on 'Game of Thrones.'
We already know that Marshall's directing the final episode of season 4, and he's said that it'll feature the battle between Night's Watch and Mance Rayder's Wildling army at Castle Black, so that's likely what's being referenced in the blog entry.
. It won't get LotR-scale awesome anyway. Which is a shaem.
