Actor So Ji Sub recently held a fan signing at for his newly released book, called 'So Ji Sub's Path'. 'So Ji Sub's path' is an essay he wrote about his experiences while filming in the Korean Demilitarized Zone back in July, which is a strip of land that runs across the Korean Peninsula that serves as a buffer zone between North and South Korea. It is also the most heavily militarized border in the world. [gallery columns=4]