This is a place where war stopped but where peace never came. The Korean war finished in 1953 without a peace treaty, leaving a line across the peninsula and a 4,000 metre-wide strip of territory that is supposed to be demilitarised.
This week, a meeting takes place in New York that might bring this Cold War anomaly to an end. North Korea will respond on Wednesday to proposals for talks between North and South Korea, the United States and China that might end in a peace agreement. Until that happens, the DMZ and Panmunjom, the "truce village" where the Military Armistice Commission is supposed to meet, is all that there is.
The closer you get to the truce village, the more serious the soldiers look: not the amiable Republic of Korea national servicemen carrying automatic rifles with no magazines, nor the genial uniformed Americans who read the news on Armed Forces television, but hard-faced men with a look of intense concentration.
The slogans on the camp signs have that curious military mixture of braggadocio and fear: "1st Battalion 506 Infantry Stands Alone", that sort of thing. And at Camp Bonifas, where the United Nations troops are based: "UN Command Security Battalion - In Front Of Them All".
This has become the unlikeliest tourist attraction in Asia, with all modern conveniences.
There is what the Americans would call a dog-and-pony show to demonstrate and explain everything before the guided tour gets under way. A US soldier whips through a slide lecture, maps, pictures, diagrams; tourists and VIPs trundle through the DMZ in limousines and coaches, from this guard post to that control point. Afterwards, souvenirs can be bought from a shop that sells mugs, cigarettes, ginseng, and ties from Pierre Balmain and Nina Ricci. This is geopolitics as entertainment.
Though it is, of course, much more deadly serious than entertainment. People get killed here from time to time. The most recent exchange of gunfire was last week, when the US Defense Secretary was taking the obligatory tour. It was a reminder that there is a vast amount of hardware arrayedhere, not just tanks and guns but a million men on either side under arms, aircraft, ships, missiles, and nuclear weapons.
The intensity of the experience is greater than that of the old Berlin Wall, somehow; these two countries fought a war in which 2 million people died in living memory. There is little contact, no Hans-Dietrich Genscher or Franz-Josef Strauss to bridge the gap, and Seoul's "Nordpolitik" has never attained the depth of Germany's "Ostpolitik".
This is total ideological confrontation, the realisation of what one Korean academic calls the "division system".
The heart of Panmunjom is a building in the main compound where meetings between the two sides were supposed to take place under the Military Armistice Commission. They broke down some years ago, though lower-level meetings still happen periodically. But the meeting room is still there, faded green baize on the table, aging microphones propped up on it and hanging from the ceiling, the translators' booths empty.
The Military Demarcation Line is marked with rusty iron panels - 1,292 of them, stretching from here to the sea on the other side of the peninsula, 240km away. A few magpies flutter through the misty air of the DMZ, but apart from that nothing moves. Everything is under constant surveillance; it is probably no exaggeration to say that every square metre is known to both sides, observed 24-hours a day. Men sit in guard posts with binoculars, constantly watching from behind reflective glass, seeing, but not seen.
There is a lot of willy-measuring going on across the DMZ. The South Koreans put up a huge flag; so the North Koreans responded with an implausibly large one, 272kg in weight, so heavy that in windy and wet weather it has to be taken down so that it does not tear itself to bits. It is 31 metres in length. Statistics of this kind are quoted with mind-numbing regularity. It flies from a gargantuan mast erected with the sole purpose of topping the South Korean one. The South Koreans have built a village, the Freedom Village, in the DMZ. So have the North Koreans, which the South calls the Propaganda Village. And vice-versa, doubtless.
Across this wasteland, the hills are alive with the sound of music, propaganda songs which drift eerily across the empty space. On a distant slope, the North Koreans have erected a message in vast letters: "Follow the Leading Star", a reference to Kim Jong Il, the North Korean leader referred to as a psychotic in the South and the Dear Leader in the North. The South Koreans have put up their own sign, which reads: "Come to the Comfortable Country".
The whole performance around the DMZ is highly stylised, ritualised even. If there is any meaning to any of this it becomes difficult, after a while, to say what it is.
There is a sense of meaning collapsing into itself, symbolism so dense that it cannot support itself, a kind of black hole. On both sides, the years of confrontation have fossilised, turning everything into an empty gesture.
There is no symmetry between North and South, of course, certainly no moral or political or economic symmetry. The South is a pleasant, prosperous place, disciplined and ordered in a Confucian way, but free. The North is a military dictatorship that spends a quarter of its national income on weapons but cannot feed its own people.
But here, in the space between the two, a third entity exists, something that is a universe in itself: pure confrontation, total uncommunication.
It may be, as the US hopes, that North and South Korea can learn to talk, and that this week will see a breakthrough.
It may be, as some in Seoul and Washington believe, that the Pyongyang regime is crumbling and reunification is possible.
Optimistically, the South is erecting a building at Panmunjom that is intended to be a customs post and immigration office. But the psychological gap to be bridged here is vast: this will not be like the unification of Germany, if it ever happens. It will be like connecting matter and anti-matter.