On the planet’s largest continent, in Asia, the Great Wall of China spans the country from East to West: but this enigmatic monument is still shrouded in mystery. Thanks to the latest digital technology, today's experts now have the means to scrutinize this UNESCO World Heritage site from all perspectives and scales, from the infinitely far to the infinitely close. History, science, construction… they dissect the work of ancient builders to try to reveal secrets kept for millennia.