North Korea is one of the world's most hermit-like countries, so it's rare to get a chance to meet people who live there. But the Chinese border town of Dandong is different. There are North Korean businessmen, waitresses and drivers. Some even speak - and sing - in English.
There is a seaside feel to this Chinese border town - its glitter-hard edge softened by the passage of river boats and wedding couples posing for photographs.
The lights strung up along the waterfront remind me of Europe. And there is music floating in from somewhere, the notes blown about in the wind.
Looking over the balustrade, across the narrow stretch of the Yalu River, it is hard to believe that the other bank is North Korea.
It is easy when living in Seoul to think that the notorious Demilitarized Zone is the only kind of border North Korea has.
The first trip inside that 4km-wide (2.5 miles) stretch of no-man's land, with its bristling weapons and twitchy atmosphere, is a shock.
But when it comes to North Korean borders, this one here in China is the biggest surprise of all.
Because the atmosphere here is so, well, different. There is no visible security, no armed guards patrolling the riverbank, no razor wire along the promenade - at least not on the Chinese side.
The other side does not look very inviting - a vista of idle factories and sludge-coloured buildings lowering in the scrubland on the opposite bank which, one Dandong local told me, had barely changed in 40 years.
The only new buildings to appear, he said, were warehouses - built to store all the goods being brought over from China.
But Dandong is North Korea's gateway to the world - a place where the long alliance between the two countries takes physical form. It is also a place to make money.
And, as a result, Dandong is full of North Koreans - party officials, businessmen and government-contracted waitresses.
If I tell you that many of my hotel staff understood only Korean, not Chinese, you will get a sense of how many visitors this city has.
Not everyone in the insular regime is banned from leaving.
I met my first members of Pyongyang's elite at breakfast.
Having studied the hotel room service menu the night before, which included an item described as "North Korea's Characteristic Grim", I was set on the breakfast buffet.
Next to me in the hotel cafe sat three middle-aged men. Their clothes were almost identical, but then so were their hairstyles, and their regulation lapel badges - bearing the portraits of North Korea's leaders. Brand new versions of them, they told me, issued just a few days before.
They told me they were investors, come to China on business. More than that, they would not say.
But this is a gold rush town for North Korean businessmen - and the evidence is lined up at the nearby cargo port.
The yard is full of trucks, dozens of them, covered in the dust of North Korea's roads and stacked with the goods that each side is hungry for - coal and other natural resources coming out of North Korea, construction materials and equipment going in.
On the wall is a timetable, notifying staff of the arrival times of the convoys from across the river.
The Chinese truckers, immersed in a game of chess by the side of the yard, nodded towards the sign: "You had better get out of here before the North Korean drivers arrive, or there will be trouble," they said.
We found them anyway. Even here, North Korea's class privileges stick, and truckers eat in different places to party officials - a string of small canteen-kitchens along a stretch of highway on the outskirts of town.
There, a dozen North Korean drivers packed into the most popular joint. They had already begun drinking and were ordering lavishly - meat, vegetables and other dishes.
They were also surprisingly friendly, at least to begin with. "Yes, I am North Korean," one of them told me, "I am heading back there later today. Where you from?"
My reply - that I was from the UK - did not seem to faze him at all.
I tried again to strike up a longer conversation, but more colleagues had begun to arrive, and suddenly no-one at the table would even make eye contact with me.
I had learned one valuable lesson though - restaurants are a great place to meet North Koreans in Dandong. And so I headed for my third meal of the day - to a hotel chain run by North Korea's own government.
There, we had more luck. Our two waitresses, both in their early twenties, took turns to ask shy questions, and flirt with our local driver. Was I married, they asked? And where on earth had I learned my few words of Korean?
North Korean agents send waitresses over to Dandong for months or years at a time, monitoring their movements and collecting their pay-packets, most of which go to the government.
One of our waitresses told us she had only recently arrived and, as if she was still in a job interview, proudly listed the subjects she had learnt at school - mathematics, chemistry, biology, and "our leader's revolution".
Her English lessons also seemed to be a highlight - mainly, perhaps, because they seem to have consisted of singing English-language songs.
"I will show you," she said. And, standing stiffly behind my chair, proceeded to sing When A Child Is Born.
"A silent wish sails the seven seas, the winds of change whisper in the trees…" Strange lyrics for an insular dictatorship to teach its children.
When she had finished, I asked her whether there was any difference between North Korea and China. "The people's minds are different," she said. "North Koreans function together, Chinese are individuals."
There are some similarities though. No-one apparently can resist the allure of a modern British supermarket.
Tesco has been a presence in Dandong for several years - a remote outpost of brand-name products, catering to affluent Chinese families and, yes, reportedly to visiting North Koreans as well.
The vats of cooking oil and barrels of cut-price chicken feet would not sit comfortably with the teabags and breakfast cereal familiar to Tesco's UK customers, but soap, shampoo and toilet paper were all said to be popular at one time among North Korea's visiting elite.
And with its large Korean-Chinese population, Dandong is a good place to stock up on Korean groceries. But what a change it must be from home.
Walking out on to Dandong's truncated Broken Bridge - a relic of the Korean War - I stand midway above the waters of the Yalu River.
From here, I can hear the music blaring from Dandong's bars and clubs, can see the neon pulsing through the falling dusk, like a mini-Las Vegas perched on the edge of the bank.
And you cannot help but wonder what they think, on the other side, watching it all from the silent, darkening shore.
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