The fimling crew is at Gosford Castle (County Armagh, near Markethill) these days, as some reports underpinned by photographic evidence from a day or two ago reveal. John Hooks posted some photos to Twitter (click to enlarge):
A similar set of photos was made available online via Samantha McClenaghan as well.
UPDATE: A sigthing of Tully banners at Gosford Castle confirms it as a Riverrun location. Here is a photo snapped by Dean, a local:
Hear Me Roar: The scaffolding outside the walls looks pretty much what we saw during the pilot shoot at Doune Castle in Scotland. I would put money on this again being a lighting rig set in front of windows for shooting indoor scenes. However, we hope they would use exterior shots as well, since the castle has a great look. People speculate that it could stand for Riverrun, not least because they have been shooting other scenes from that part of the story around this time.