As a result, the tourist sites we were allowed to visit, the roads along the way and the surrounding countryside were cleared of locals - some even dashing inside their houses as the tourist convoy approached.
We did see a few ordinary folk in the border city Gaeseong, mostly walking, some on cycles, all wearing worn, baggy clothes. But even there, soldiers were out in force directing them to the opposite side of the road to us and keeping them away from the ancient sites we were visiting.
I tried waving from the bus but was stolidly ignored, apart from a toddler who waved back, inspiring his parents to break into proud smiles.
An old man shuffling along the footpath started to cross the road to where our bus was slowing to turn a corner, provoking a gold-braided officer into an outburst of waving, shouting and pointing, and sending soldiers running to restore order.
Meanwhile inside our bus our two minders, smiling, good-looking men in nicely cut dark suits, sporting Kim Il Sung lapel badges, were exuding charm and cracking jokes; one even sang two North Korean songs in a pleasant tenor voice.
I asked the singing minder, care of a Swiss tourist who spoke Korean, why no one was around. He explained that the previous day had been Kim Il Sung's birthday, and people were enjoying a celebratory holiday.
But, if it was a holiday, wouldn't people be out fishing and playing? No, he said cheerfully, it was traditional to spend the morning of a holiday resting. If we returned in the afternoon we would see locals out relaxing.
There are also strict rules to prevent foreigners exploiting the tours. It is forbidden to take mobiles, laptops, MP3 players, high-powered binoculars, South Korean newspapers or magazines and camera lenses bigger than 150mm.
Visitors are prohibited from taking photos from the buses, photographing North Korean people or facilities, or taking any shots outside the tourist sites.
It's a pity, because the landscape is rather picturesque, not least because there are no power and phone lines, fences, walls, advertising hoardings, roadside rubbish, commercial developments and urban sprawl, meaning the countryside is as unspoiled as you imagine New Zealand might have been a century ago.
I wasn't even allowed to get a shot of a giant statue of the Great Leader which towers impressively above Gaeseong, though no one stopped me photographing a display showing him "offering on the spot advice" to grateful farmers, metalworkers, engineers and train drivers, erected outside one of the museums we visited.
Between cracking jokes, our two minders, and the numerous guards at each of our stopping points, kept a watchful eye out for breaches - a Finnish photographer on our bus was made to delete unauthorised pictures they caught him taking - and when we departed North Korea the frontier guards checked every shot in my camera (about 350 of them) to ensure they were acceptable.
Despite all the controls, it was a relaxed outing with no sense of menace. The sites we visited during our tour were pleasant, picturesque and well maintained. The guides were charming and well informed. And we were very well fed.
The UN's World Food programme says a quarter of North Korea's population faces starvation, and the Buddhist humanitarian group Good Friends has reported peasants bulking their food up with tree bark and grass. We were served, however, the region's famous royal table banquet, with neither grass nor bark in sight.
This is a 13-dish feast with an amazing array of fish, meat, egg, various vegetables and sweetmeats - plus soup and rice, which form the centre piece of most Korean meals - all served on brass tableware.
It was a sumptuous meal, far more than I could eat, and presumably designed to show that whatever lies the regime's enemies might tell, there is plenty of food for all.
As to the truth of that, and everything else, it was impossible for us to find out, but the trip nevertheless provided a fascinating glimpse of life inside the most secretive of countries.
The particular tour I went on, has been running only since December. As part of the north's grudging quid pro quo for vast amounts of aid from South Korea - including the creation of a huge industrial area in Gaeseong city financed, built, run and even powered by the south - 500 people a day are allowed to cross the border for a nine hour visit.
Almost all those who go are, of course, South Koreans taking the opportunity to see the other half of their homeland, cut off for more than half a century and where many have relations they have never known.
It must be a strange feeling entering this part of their country, effectively a foreign land. When I remarked to our guide, Hyun Sook Park, that it was quite exciting to be crossing the most heavily militarised border in the world - guarded by 1.8m troops - she replied, "It is exciting for me, too, but I think my feeling is different.
"Both sides are my country, really. My husband's uncle has a wife in the north who was cut off by the border and he does not even know if she is alive. Many people have stories like that. So it is a special feeling to be able to come here even if only for a day."
Between the two halves of Korea lies the demilitarised zone created after the Korean War. Its borders are heavily guarded, but the 4km in between is mostly a tranquil haven of forest and grassland which has become an important wildlife refuge.
There are two sets of customs and two transit centres, the South's to stamp passports in the usual way, the North's to check our IDs, which come with the warning, "Do not damage this or you will be fined."
The route across the border is a sealed highway lined with barbed wire and crossed by several guarded gates. For the first half we were escorted by a South Korean Army jeep, but at the midway point, marked by nothing more dramatic than a dark grey strip across the road and a sign saying "Goodbye", it pulled aside and a North Korean jeep waving a red flag took its place. We had entered the mysterious Hermit Kingdom.
CHECKLIST
Getting there: Korean Air flies direct from Auckland to Seoul.
North Korea tours: Fathom Asia has day tours from Seoul to Gaeseong.
Further information: See visitkorea.or.kr.
Jim Eagles visited Korea as guest of the Korean National Tourism Organisation.
