Mary Dejevsky: Into the frozen heart of Asia's cold war

South Korea's capital offers peculiar mismatches. The city centre, ravaged by war half a century ago, is now a forest of high-rises divided by broad boulevards, with a labyrinth of metro lines and shopping malls underneath. But enter the grounds of any one of five palaces scattered around the city, and you find yourself in a haven of parkland and pagodas, with the high-rises still visible all around.

The most striking dissonance, however, is between the 10 million-strong modern city living an ostensibly relaxed modern life, and the proximity, less than an hour's drive away, of one of the world's most sensitive borders. Indeed, it is inaccurate to call it a border; the 240km long demilitarised zone (DMZ), studded with land mines, aerials and watchtowers and girded with layers of barbed wire, is the still-temporary solution to a war that is even now not officially over.

Yet, as the world agonises about the mortal threat from a nuclear-armed North Korea, Seoul gives every impression of turning the other way. The DMZ, where there has been no fatality for more than 20 years, has become a nice little earner for the city's tour companies, who take daily bus-loads of the curious into the frozen heart of Asia's cold war.

As you near the border, you can contrast the forested hills of the South with the bare hills of the North – where they are said to have cut down the trees for fuel or food. In the DMZ, all the paraphernalia of imminent armed confrontation is there. US and South Korean troops patrol. To be admitted, you must sign away liability for your death or injury; then you can gaze across the demarcation line, watching Them tracking You.

But for all the 007 drama, the hair-trigger tension I sensed to the very end in cold-war Berlin is almost not there. The building that straddles the border, equipped for peace talks that have still not been consummated, feels less like a war zone and more like the railway carriage in the woods at Compiègne where the First World War armistice was signed.

Only outside the DMZ, in a bizarre amusement park, do you start to glimpse the human side. A bullet-ridden railway engine, caught in the last of the hostilities in 1953, was installed – recently – as a relic, while the lower branches of trees are festooned with ribbons inscribed by those hoping to be reunited with relatives in the North. Oh yes, and when you leave the DMZ, the duty soldier gives you back your signed liability form, as a grim souvenir.

A man of 28 letters

An enormous statue has just been unveiled in the centre of the city. You might think, given the division of Korea, the living memory of war and the proximity of the nuclear-aspiring North, that it would be a warrior. Not at all. It depicts King Sejong (1397-1450), whose claim to immortality is that he devised the Korean alphabet, and he is holding not a weapon, but a book. The King, it is said, wanted to make it easier for his fellow countrymen to read and write, so he replaced the Chinese system of ideograms with the ingenious, and unique, 28-letter alphabet, that is used to this day.