The fantasy epic, The Great Wall, with Oscar-winner Matt Damon and other stars, will hit Chinese theaters on Friday. [Photo provided to China Daily]

For over 2,000 years, the Great Wall has stood as a barrier shielding the country from invaders, but in the movie penned by three American writers, the wall is a weapon-filled base for an elite force fighting an army of monsters, Tao Tie (greedy for food), which hunt humankind every 60 years.

Zhang says the monsters based on The Classic of Mountains and Seas have characteristics found in Chinese mythology.

"They were designed to be large predators, not alien creatures. Just like they were depicted in the ancient volumes, the Tao Tie (in the film) have eyes in their armpits," he says.

Ancient China's cutting-edge inventions as well as the country's traditional musical instruments and costumes can be seen in the film.