North-South Korea Border
The roughly 248 km-long Military Demarcation Line between North and South Korea is a forbidding and heavily militarized place.
Tours of the DMZ can be arranged in Seoul and are an amazing experience. Visitors are taken to the now deserted village of Panmunjom (Panmunjeom), 53km from Seoul. Main points of interest on your organized tour are the Joint Security Area and the Third Tunnel (dug by North Korea to try to infiltrate the South) and Camp Bonifas - "In Front of Them All".
T1 through T3, in the Joint Security Area (JSA) are conference rooms (image below) right on the "border" between the two Koreas.