Aquatic farms extend almost four miles off the coast of northeast China’s Liaoning Province. These fish farms, built out on shallow sea beds and mud flats, are big enough to be visible from space. 

The image above comes from an astronaut on the International Space Station, who shot a contrasting image of the coastline’s green terrestrial agriculture and the beige aquaculture in early September. Most of the space is dedicated to shellfish cultivation (77 percent of China’s aquaculture production), while 5 percent is marine fish. The vast majority of the farmed marine creatures are sold live in Chinese markets, rather than processed and sold abroad. 

These aren't the only human-constructed objects visible from space—or even in China. The Great Wall can occasionally, sort of, be seen from the ISS—but only barely, with the help of a camera zoom lens, not with the naked eye.