Military Demarcation Line Introduction: The North-South Military Demarcation Line is 241 kilometers long and has a total of 1,291 yellow boundary markers. The top side facing South Korea is written in English and Korean, and the side facing North Korea is written in Korean and Chinese. North Korean, American, and South Korean security personnel face each other across a 5-centimetre-high military demarcation line, and neither side is allowed to cross a step.