For one month every year, millions of tourists descend upon the small county of Luoping in southern China to see its oceans of rapeseed flowers. The little yellow blossoms are part of a multibillion dollar industry producing everything from canola oil to biodiesel and honey. 

But that's not all – in neighboring Xuanwei County is a tiny village producing China's answer to prosciutto ham, while on the outskirts of Qujing City, we find the humble source of the great Pearl River system. 

Aerial footage from Travelogue's Pearl River Series: Mouth to Source