"Game of Thrones" season 4 is currently being filmed in Ireland, which is the location for scenes taking place at The Vale. However, filming season 4 is proving to be anything but easy.

Writer and executive producer David Benioff told EW.com about the challenges the cast and crew have had to face while filming season four of "Game of Thrones."

"It's the toughest production schedule we've ever had," Benioff said at Comic-Con. "We got more action, which is obviously more time consuming. It's a brutal shooting season ahead. But if we can make it through, yeah, I think it's going to surpass season three. The last 3 episodes, there's so many scenes we've been waiting for so long to do. And it just gets more and more fun to write for these characters. After three years of doing it, we have that much more comfort to make everything uncomfortable for them. We're very excited for it. Season five gives me nightmares, but [not season four]."

Benioff was referring to the difficulty of adapting the books by George R.R. Martin to the television screen. The season three finale finished roughly two-thirds of the way through the third Ice and Fire novel, "A Storm of Swords," out of five in the series.

According to EW.com, the fourth book, "A Feast for Crows" will be much more difficult to adapt, as it includes a slew of new characters and tangents while omitting some beloved names like Tyrion, Jon and Daenerys.

Despite the challenges posed by the upcoming season's filming schedule, "Game of Thrones" star Peter Dinklage, called the script "my favorite so far of the whole series."