The Forbidden Country geocache (GC2F0R6) was placed in North Korea by spagr in September 2010. It is the only geocache ever published in that country.
The problem is not the hiding place but the law: GPS devices are forbidden to visitors, who have to leave them at the airport. The listing therefore offered an alternative for anyone unable — or not permitted — to look for the container: bring back four photographs proving they had been in the country.
Found only once before it was archived, nobody really knows whether a cache was ever actually placed there.
The text published on the cache page was no ordinary geocaching text. It mainly invited readers to form their own opinion of the country, with a heavy political undertone, which goes against the rules of geocaching.
The answer : 4
The only geocache ever published in North Korea, where GPS units are taken at the airport. Found just once before being archived, over a text whose political undertone broke the rules.