Last night's Game of Thrones featured one of the most epic battles in the show's history, and now star Kit Harington is opening up about what it took to make that scene come alive.

E! Online reported that this week's episode featured a battle between the army of the undead (White Walkers) and a Wildling camp, located north of the wall. Jon Snow is caught in the middle of this battle.

The final battle scene lasted for over twenty minutes, USA Today added.

Harington opened up about what it was like to make that storyline a reality."You just know when an episode is good and when it's not, and I felt last night's was really, really, really great episode for the series," Harington told E! News. "I thought the end product of what they produced for 'Hardhome' was amazing."

The entire scene took a month to film."We spent a month filming that sequence which was 20 minutes long. A month, a solid month. It equated to about a minute of footage a day. It was heavy and it was important to me that it worked because it's a really important beat in the Game of Thrones story. I thought it was brilliant. I really, really loved it," said Harington. "I was so proud of it and happy with it. I never pat myself on the back but I thought, why not? It was great!"

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