Yellow river, ChinaNorth China Plain

This is the third-longest river in Asia, and the most silt-laden river on Earth. It takes its name from coloration by the fine, wind-blown sediment, known as loess, that it carries along its lower course. The river flows through deep gorges, as seen in the image, before it descends on to the North China Plain. Hiddleston jumps in. “Nobody ever gives him enough credit for this,” he says, turning to his co-star. “Seriously, you’ve been here since what time? He’s been on set working as an actor all day, and then he has to go and train afterwards. 

There’s not many people who can do that.”

After talking of their excitement at working with Waititi the two say goodbye, and we return to the set to watch another couple of hours of filming.

Photograph: Qin0377.