Panmunjom is a village on the border between DPRK and ROK, where the 1953 armistice that halted the Korean War was signed. The building where the armistice was signed still stands, though it is on the northern side of the Military Demarcation Line, which runs through the middle of the Demilitarized Zone.
The Korean Demilitarized Zone is a strip of land running across the Korean Peninsula that serves as a buffer zone between DPRK and ROK. The DMZ cuts the Korean Peninsula roughly in half, crossing the 38th parallel on an angle, with the west end of the DMZ lying south of the parallel and the east end lying north of it. It is 250 km long, approximately 4 km wide and is considered as the most heavily militarized border in the world.