North Korea is a country in East Asia. It is impossible to enter North Korea through South Korea, (or from North Korea to South Korea.)
North Korea used to be a thriving center of Christianity. The capital, Pyongyang, was known as the Jerusalem of the East. But due to the oppressive government, Christians have to worship underground and are persecuted.
There are around 5 people groups in North Korea and of those, 2 of them (around 40%) are unreached. The population is around 25,762,000. Of those, 99.3% are unreached.
There is no religious freedom and all North Koreans must follow the Juche religion. There are around 1.66% of Christians in North Korea.
It is a very dangerous county. People are faced with imprisonment, torture, and even death. Anyone discovered as a Christian, or anyone who expresses interest in Christianity is considered an enemy of the state. It is ranked 2nd in the persecution ranking (1 being the highest).