This eccentric corner of North Korea, right on the border with China and Russia, has been designated a ‘free-trade zone’ since 1991. The two towns of Rajin (라진) and Sonbong (선봉), usually referred to collectively as Rason, are both unremarkable industrial ports surrounded by attractive hills, wetlands and forest. Rajin-Sonbong's rocky cliffs, lakes and sandy coastline are uniquely beautiful, but it feels like the end of the world and very few tourists make it here.