Here's what's going on in this picture: 1) The soldier in the foreground is with the U.S. army and serves as tour guide whenever groups pass through the DMZ. 2) The four guys in dark green coats are South Korean military. They stand guard in what is apparently a taekwondo "readiness" position throughout the duration of the tour. 3) The light blue buildings are UN facilities. The building on the left is the one we're about to enter. 4) The dark slab of concrete in roughly the center of the photo marks the military demarcation line. Everything "below" the concrete slab is part of South Korea, and everything "above" it is North Korean territory.