HBO has released a new video, narrated by Charles Dance, chronicling the creation and production of its sprawling epic series, Game of Thrones.

This video offers insight into how grand a scale the show is shot on as well as an in-depth look into how Game of Thrones came into being.

There are so many characters and story lines on such a grand scale for this show, it shoots at 100 locations with 257 cast members! (that is not to mention the 700 crew members and 4,000 props). This show is literally a 365 day a year job for executive producers David Benioff and Dan Weiss.

Season 4 of Game of Thrones premieres April 6 on HBO. You can view the  latest trailer below: