China + North Korea
Even after two American journalists were sentenced to 12 years of hard labor for illegally crossing into North Korea from China in 2009 (they were eventually freed), foreigners continue to fall afoul of overly anxious border cops. In August 2010, President Jimmy Carter had to fetch American Aijalon Mahli Gomes, who may have crossed over on a personal humanitarian mission. Dying to see North Korea? Visit the tourist-friendly Demilitarized Zone that separates the two Koreas, where you can legally walk on northern soil—at least for a few minutes.