The Wall that defends the Game of Thrones universe would need to be made of more than pure ice if it had stood for over 8,000 years.

According to the plot of George R. R. Martin’s famous book and television series, the massive wall of ice protects humanity from the blue-eyed White Walkers, an ancient race of ice zombies that threaten all living things. But if the wall that shields the realm was made of pure water ice, it would not remain a wall for long; instead, it would quickly become a