A series of tunnels from N. Korea were discovered leading under the DMZ. I believe four have been discoverd, the last being found in 1990. Each one has been blown through granite & all lead to S. Korea. When the first tunnel was discovered, it had electricity, railways and paths for vehicles. While difficult to see, this ride on tracks takes you deep into the Third Infiltration Tunnel. Yes, you're required to wear helmets & need them for the low ceiling! When you're inside the tunnel, it provides you an idea of what it has taken to create these.
This is Dorasan Train Station next to the DMZ. It may have opened since I've visited, for a strict trial run to N. Korea. These guards are positioned for picture taking & most of us tourists line up for a photo. Yes, I have the physical picture in my room.
Pictures can only be taken from behind a line not shown here. However, these pay scopes allow you to peak at N. Korea.
The town of Panmunjom is shown here in the distance. Other than this town, the DMZ is devoid of humans and their machinery. I should mention there is still a large number of landmines that exist in the Demilitarization Zone.