Hundreds of defectors make the perilous journey every year, and now it's become even more arduous.
North Korean defectors
By Tom Brada
By Michael Madden
North Korea leadership expert, Stimson Centre
By Julie Yoonnyung Lee
Thae Yong-ho is one of the highest ranking North Korean officials ever to defect. He's been talking to the BBC's Steve Evans about the regime.
Yu Hyun-joo was a propaganda .and member in North Korea before her defection
22-year-old Nara barely knew what social media is before her defection from North Korea.
The incredible tale of the North Korean prison guard and prisoner who broke out of a detention centre together to flee the country's repressive regime.Copyright: BBC
By Laura Bicker
BBC News, Seoul