There are no guns in their holsters, but their stares are as icy as the snow falling on the ground they patrol along the world's last Cold War frontier.

They are soldiers from North Korean dictator Kim Jong-Il's army and, as threatening as the Americans make them out to be, they are also a top attraction on one of the most surreal tourist trips in the world.

The soldiers patrol the northern side of the Demilitarised Zone (DMZ), the four-kilometre (2.4-mile) buffer between North and South Korea created when their 1950-53 war ended with an armistice.

On the southern side of the DMZ are the South Korean and US forces from the United Nations Command (UNC), the global body that protects South Korea from another potential Stalinist invasion.

At their closest point, soldiers - and tourists - are just inches apart and separated by nothing but an imaginary border.

In the 50 years the DMZ has been in place, North Korea and the UNC have staged such a massive arms buildup it is now the most heavily militarised place in the world.

But as Kim leads his already hermetic nation further into isolation with threats to restart a nuclear programme, and with foreigners virtually banned from entering the country, the DMZ is a unique lure.

"People come here to see a North Korean soldier staring at them. It's an adrenaline rush," US Captain Brian Davies tells reporters inside the DMZ.

"People just like to say: 'Hey, that's a North Korean soldier and he is looking at me'."

Such interest has even evoked interest in Hollywood, which filmed a scene for the latest James Bond film 'Die Another Day' set in the joint security area where meetings between the UNC and North Korean officials hold meetings.

Before reporters were allowed to get too close to the soldiers, they were warned by the US troops patrolling the south side of the imaginary line.

"The Korean peninsula is still technically at war," US Lieutenant Colonel Matt Margotta says dramatically.

"North Korea has 1.1 million soldiers: 70 percent of them are within 100 miles of the DMZ."

No sudden moves, warns another US serviceman, and no sudden hand movements which could spark a violent response from a patrolling North Korean soldier. And don't even think about crossing the line into North Korea, they add.

They also evoked a tale of two US soldiers hacked to death in 1976 by a 30-strong group of axe-wielding North Korean guards in a dispute over a tree.

Up close, the North Korean soldiers look menacingly strong and surprisingly well fed, considering about two million of their compatriots have died of starvation since the mid-1990s.

But as the US military advisers explain, both UNC and North Korean sides ensure only their biggest and best soldiers are present in the DMZ.

For more than 15 minutes, the press pack snaps photos of the guards, who stand rigid and barely blink. Other North Korean soliders peek out from behind a curtain in a nearby building.

"They're watching us," a US soldier says. "They're always watching us and we are always watching them."

Increasingly, so too are civilians who are doing their own Cold War reconnaissance.

The UNC offers free tours to young South Koreans to give them a sense of the threat the nation has faced since the end of the war.

For foreign tourists, brochures at hotels offer day tours for 54 000 won (US$45).

"This is a very visible symbol that this armistice is still alive," Colonel Margotta says.

"You have got a whole new generation growing up in Korea right now who don't really know the contribution here. You are bringing kids up here to see a Korean People's Army soldier. It brings it home to them."

The tour includes a walk through the UNC military armistice room, split down the middle with one half belonging to each side - the line an inviolate "do not cross" even for meetings of high-ranking military officials.

When the room is vacant, tourists are allowed to wander over and technically stand in North Korean territory, while a Stalinist soldier peers in from the window.

It is a bizarre experience only tourists from the south may experience.

UNC officials say fewer than 9000 North Korean civilians show up near the DMZ each year and an incident in 1984 perhaps explains why.

A North Korean tour from the Soviet Embassy to the joint security area that November was marred by the defection of a Russian interpreter, who sprinted across the imaginary border towards UNC soldiers.

The US version of events claims the North Koreans opened fire, killing a South Korean soldier but missing the Russian.

It is one of many stories told on the tour that imparts to civilians the depressing reality that the Iron Curtain may have fallen, but the Cold War is as strong as ever on the DMZ.

AFP