Location filming in Croatia began yesterday at the Trsteno Arboretum. Natalie Dormer, Gwendoline Christie, and Dame Diana Rigg featured in the scene, said to be a part of the fourth season’s first episode.
The Icelandic website Vísir reports they are shooting at Þingvellir today, one of the three known locations of this years two-week sojourn of the GoT team in Iceland.
An Icelandic news site is reporting that Game of Thrones will begin filming next week, and three different locations will be used by production while in Iceland.
An extras casting notice from Embassy Films appears to provide filming dates for season 4 of Game of Thrones in Croatia, and confirms the city of Split as a new location for next season.