It's no secret that the Republic of Korea (the south) and the Democratic People's Republic of Korea (the north) officially aren't the best of friends. There is a four kilometre wide strip of land dividing the two countries, across which they peer suspiciously at each other, and occasionally have a minor go. This is the Demilitarised Zone or "DMZ" (with a "zee" sound, y'all) and it is the most heavily fortified frontier in the world today. Right in the middle of it, is Panmunjom.

Although it is perfectly possible to visit North Korea properly on a tour from Beijing, I couldn't resist taking an opportunistic jaunt up to the DMZ from Seoul. There seemed to be all sorts of different tours and rules to get there, but I took a trip with a tour company based in the Lotte Hotel, which required that I dress smartly, take my passport, not be from any of a lengthy list of countries, and sign a death waiver. The scene was set...

Welcome to the DMZ. This happy sign belies the seriousness of the place, at the Third Tunnel of Aggression entrance. Occasionally the north have a shot at tunnelling under the DMZ, this was one such site which was uncovered and intercepted by a South Korean tunnel boring machine in 1978. I went in the tunnel, but unfortunately, no photos allowed.

The Joint Security Area is the nexus of the DMZ, where soldiers from north and south stare across the military demarcation line at each other, the de facto border between the two countries. The border is the low concrete strip, behind which the North Korean soldiers stand in formation in their dark uniforms. The building in the background is the North Korean border post.

It is possible to temporarily enter one of the blue huts that straddle the border, when accompanied by two South Korean soldiers.

One foot in the north, one foot in the south. The three microphones on this table mark the border, South Korea is on the left, North Korea on the right. I don't know how often actual negotiations take place around this table.

I took this whilst standing entirely in North Korea. The small concrete strip is the border, and the South Korean soldiers stand half hidden behind the huts, with their highly reflective sunglasses so the north don't know what they're looking at.

One of the South Korean soldiers guards the door to North Korea. Not to stop us from walking out (which would doubtless mean summary execution) but to stop the North Koreans coming in and stealing us. It's happened before.

The North Korean border building sported a similar motley group of tourists, who weren't allowed any closer than the door. Although I did notice that they didn't have a dress code. Our guide was very excited, this was a rare occurance.

Looking across the DMZ to the North Korean propaganda village and the world's tallest flagpole. The days of flagpole envy and blasting propaganda and K-Pop across the DMZ are behind us.

The Military Demarcation Line or "border" to you and I, is marked by these small white posts. Either North Korea want to keep their forest for cover to snoop around in, or they simply haven't paid their gardener for a while.

The Bridge of No Return. After the armistice marked the end of Korean War fighting, POWs in the south were taken to this bridge and offered the choice to return to their own country. But they were told in no uncertain terms that they wouldn't be allowed back again. The bridge still straddles the border today.

Just outside the DMZ there were less restrictions on photography, but still heavy fortifications, which had started appearing at barely the outskirts of Seoul. This is the railway line heading up to North Korea.

Ribbons expressing the desire of South Koreans for unity, and to be reunited with their estranged relatives in the north.

North Korean money for sale. Disappointingly, I couldn't afford it (it was that or lunch). It's illegal to export cash from North Korea, so someone took a real risk getting this out of the country.

Blocked path to a former bridge crossing the river into the DMZ.

Elsewhere in the DMZ the South Koreans have set up a spying station for having a good peer across the border to check up on their northern cousins.

You too can join in the fun for just a few won, using these high powered binoculars to check out the North Korean propaganda village. The village is seemingly just a series of empty buildings without even windows, all for show to the south. Even these binoculars weren't powerful enough at this distance to be sure.

The DMZ is peppered with monuments to the underlying wish for reunification. Here the two halves of Korea are pushed back together.

Back on the deserted highway and it was only a couple of hundred clicks to Pyeongyang. We wouldn't get any further than the transit office. Gaeseong is the joint industrial area just within North Korea, an uneasy place from which the South Korean investors are regularly expelled.

Poised and ready for the day of reunification, Dorasan railway station for now sits clean, shiny, empty and lifeless. Even if you got past the squaddie at the turnstile, you'd have to wait a mighty long time for a train to Pyeongyang.

Ever optimistic, even the advertising in Dorasan station looks forward to the day when a direct rail service will run from Seoul to London.

Security and immigration hall in Dorasan station.

The Inter-Korean Transit Office was doing its usual roaring trade.

Mural in Dorasan station again calling for reunification. I have no doubt it will happen one day, but as to when, and at what cost, remains to be seen.