We know very little about the Democratic People's Republic of Korea.

The North Korean government is notoriously secretive. Upon entering the country, visitors are instructed on what they can and cannot take pictures of. Customs agents inspect cellphones and other digital devices — including cameras, tablets, and storage cards — for banned content.

In 2015, these restrictions prompted Xiaolu Chu, a Getty photographer, to travel by train through the country, documenting everyday life through his phone's lens. He told Business Insider it was too risky to use a high-end camera because locals could report him to the authorities.

While some images were deleted during run-ins with the police, Chu shared some snapshots with Business Insider. Take a look at life inside North Korea.