The Third Infiltration Tunnel

By the DMZ Tour Tickets Editorial Team · Published from Seoul, South Korea

Quick answerThe Third Infiltration Tunnel is the most visited site inside the DMZ and the highlight of almost every tour from Seoul. Discovered in 1978, it is one of four known tunnels dug by North Korea under the border toward Seoul, wide and tall enough to move thousands of soldiers an hour. Today visitors descend deep underground to walk part of its length toward the demarcation line.

What it is

Discovered in 1978, the Third Tunnel is one of four known tunnels dug by North Korea toward Seoul. It runs more than a kilometer and lies deep below the surface, built to move large numbers of troops quickly and secretly across the border.

The visit

You reach the tunnel by a steep access ramp on foot or by a small monorail on some tours. Inside, the passage is low and damp, so helmets are provided and taller visitors need to stoop. The climb back to the surface is the tiring part, but most people manage it at their own pace.

How to visit

The Third Tunnel is included on nearly every half day and full day DMZ tour from Seoul, so you do not need to seek it out separately. Cameras and bags must be left in lockers before you go down, and you cannot enter the DMZ independently to reach it.

Frequently Asked Questions

Can you walk through the whole Third Tunnel?

No. Visitors walk a section of the tunnel toward the demarcation line but are stopped well before the border by a series of barricades. You still go deep underground for a real sense of its scale.

Are cameras allowed in the Third Tunnel?

No. Cameras, phones and bags must be left in lockers before you descend, for security reasons. You can take photos above ground at the exhibition area.

Is the Third Tunnel suitable for everyone?

The steep ramp and low ceiling make it hard for those with mobility issues or strong claustrophobia. Most visitors manage fine, and you can wait above ground if you prefer.