I knew that BuzzFeed News was trying to expand its reach, but I didn’t think it would take on as complex a project as in-depth reporting on China’s insane genocide of its Uighur Muslims.

Then last week, the site dropped two stories that emerged after Megha Rajagopalan, their Middle East correspondent, spent major time in neighboring Kazakhstan interviewing those Muslims who had managed to get out of China.

The first of a two-part expose starts off with satellite photos of the prison camps of western China and this statement: “China rounded up so many Muslims in Xinjiang that there wasn’t enough space to hold them.” And then:

In the most extensive investigation of China’s internment camp system ever done using publicly available satellite images, coupled with dozens of interviews with former detainees, BuzzFeed News identified more than 260 structures built since 2017 and bearing the hallmarks of fortified detention compounds. There is at least one in nearly every county in the far-west region of Xinjiang. During that time, the investigation shows, China has established a sprawling system to detain and incarcerate hundreds of thousands of Uighurs, Kazakhs, and other Muslim minorities, in what is already the largest-scale detention of ethnic and religious minorities since World War II.

How was this done?

BuzzFeed News identified 268 newly built compounds by cross-referencing blanked-out areas on Baidu Maps — a Google Maps–like tool that’s widely used in China — with images from external satellite data providers. These compounds often contained multiple detention facilities.

Adding that it had employed Alison Killing, a licensed architect as one of the reporters on the story, BuzzFeed was able to figure out that these were buildings that could easily hold 10,000 inmates each. This story even went into what these places looked like inside.

Unlike early sites, the new facilities appear more permanent and prisonlike, similar in construction to high-security prisons in other parts of China. The most highly fortified compounds offer little space between buildings, tiny concrete-walled yards, heavy masonry construction, and long networks of corridors with cells down either side.