For decades, the Democratic People’s Republic of Korea – more commonly known as North Korea – has been one of the world’s most secretive countries.
Its government doesn’t like people from outside the country going there and finding out what’s going on.
It shares a border with a country called South Korea – and the two countries have not gone on with each other for a long time.
A North Korean leader has not stepped foot in South Korea for 65 years and the leaders of the countries have not met for 10 years.
But that has just changed.
North Korea was formally created on 9 September 1948, following the end of the Second World War, along with another country called South Korea.
The political differences between the two rival states led to the outbreak of a horrific war in 1950, which lasted three years.
Since then, North Korea and South Korea have been enemies.