Get a glimpse of the front lines of the DMZ at Sangseung Observation Post (OP), a fully functioning observation post that monitors North Korean troop movements 24 hours a day. Visitors to Sangseung OP can get a look at both North Korean soldiers and their facilities right across the DMZ as well as the gorgeous wildlife that has developed inside the DMZ itself.
The 1st Infiltration Tunnel was discovered on November 15, 1974, by a South Korean reconnaissance team who spotted steam rising from the ground. As they investigated, a North Korean guard post opened fire on their team. A few days later a larger team went over to investigate, but upon entering the tunnel triggered an explosive device, killing one American and one South Korean soldier and wounding six others. Because the tunnel is located inside the DMZ it is inaccessible to tourists. However, a mock recreation of the discovery of the tunnel as well as information about it is situated right by the Sangseung OP.
Visitors must bring their passports in order to gain admission to the post. Admission is prohibited without one (Exception: children and teenagers accompanied by adults).