They enter China legally via the Sino-Korean Friendship Bridge or sneak into the country by swimming across the Yalu River under cover of darkness.
The legal migrants come to work in Dandong's kitchens and construction sites under an agreement with Pyongyang, while the refugees try to melt into the cities and countryside, always fearful of being sent home to be executed or imprisoned.
The appearance of these North Korean laborers, who work in China with the blessing of the North Korean government, provides ordinary Chinese with little indication of how desperately poor the vast majority of people in the neighboring country truly are, however. In fact, most people in Dandong are seemingly unaware that far more common than the contract workers who come to China legally are those thousands of North Koreans who sneak across the border each year in search of something resembling a normal life -- not one dominated by hunger and fear.
Indeed, the closer to the secretive dictatorship, the more misconceptions seem to exist about life there. Residents of Dandong see the North Koreans in their midst as benign neighbors whose own homeland resembles China of yesteryear.
"There is really nothing special or strange about North Koreans," said longtime Dandong resident Wang Dan, 45, who adds that she and others in her hometown “think of them like Americans probably think of Mexicans or Canadians -- just people from the neighboring country.”
The comment is indicative of the fact that many Chinese do not have sufficient information on what is really happening in North Korea, said Greg Scarlatoiu, executive director of the Committee for Human Rights in North Korea, an NGO based in Washington, D.C, which, he adds, "is intentional on the part of the [Chinese] government."
Dandong, whose population of 2.5 million makes it a small city by Chinese standards, is the main conduit for a brisk cross-border trade between the neighboring countries. In 2011, the Chinese government estimated that trade with the Hermit Kingdom was close to $6 billion.
China is far and away North Korea's biggest trading partner, accounting for 60 percent of the nation's exports, and while trade with the rogue state makes up only a miniscule percentage of China's trade overall, three-quarters of it is channeled through Dandong.
“Since the early 2000s, Beijing began efforts to change the nature of its relationship with North Korea from one of aid to trade," said John Park, Northeast Asian security specialist at Harvard's Kennedy School. "The bulk of the bilateral trade is related to North Korea's export of coal and iron ore to Chinese partners and clients."
Dandong is home to thousands of Chinese of Korean descent who came to China before and during the Korean War, as well as current North Korean citizens, many of whom are contract workers that North Korea allows to work in Dandong's restaurants, albeit under the watchful eye of government minders and with most of their earnings going directly to the state, said Greg Scarlatoiu, executive director of the Committee for Human Rights in North Korea, an NGO based in Washington, D.C.
According to recently released statistics from China's National Tourism Association, the government granted 93,300 work visas to North Koreans in 2013, a 17-percent increase over the previous year.
Other North Koreans seem to have carved out a more permanent existence in the seaside city, some even owning small businesses and raising families there. The legal status of these migrants is not clear, however.
Because it is a crime for North Koreans to flee the economically-starved nation, those who escape don't have the proper documentation to settle in China and are under the constant threat of deportation. Tens of thousands of North Korean refugees are essentially living in hiding in the northern Chinese countryside, permanently fearful of being discovered by either the Chinese or North Korean authorities and repatriated.
"Many refugees are unlucky when they reach China -- they exchange one circle of Hell for another," says Melanie Kirkpatrick, a senior fellow at the Hudson Institute and author of "Escape from North Korea: the Untold Story of Asia's Underground Railroad." "These people, especially the women, are extremely vulnerable. I've heard stories of bride brokers and brothel owners paying lookouts on the border to call them if a pretty North Korean woman appears on their door."
Since Kim Jong-un took power in December 2011, following his father’s death, crackdowns have intensified. North Korean officials are said to operate freely within China, forcibly bringing refugees back home to face execution or imprisonment in one of the country's notorious prison camps.
It has also become increasingly more difficult to cross into China at all, say refugees who have made it safely across the border in recent months.
Through a network of refugees with whom she is in close contact, Kirkpatrick has learned that.
"Since Kim Jong-un came to power, he has had watchtowers with machine guns installed on the border and issued 'shoot to kill orders,'” Kirkpatrick said. "He has closed down villages on the North Korean side to reduce the number of routes out of the country and enacted stiffer punishments" on those caught trying to flee.
Statistics bear out the veracity of these stories. In 2011, according to the South Korean Ministry of Unification in Seoul, 2,727 North Koreans, almost all of whom fled through China, reached safety in South Korea. In 2012, the first full year after Kim Jong-un took over, that number was nearly halved to 1,502.
While China is concerned about instability related to a refugee crisis should the Kim dynasty fall, a bigger concern to Beijing is a reunified Korean Peninsula aligned with the West.
“Chinese government think tank analysts are not confident that South Korea would maintain its China-friendly policy [and] a pro-U.S. unified Korea on China's doorstep is not a welcome prospect,” Park said.
Kim Jong-un, a wild card to the world, is one to China, as well. The point man for the trade alliances with China had long been his uncle, Jang Song Taek, who Kim Jong-un recently had executed. Experts agree that Jang's execution casts a shadow on China-North Korea relations, but it is unlikely that his death will cause the Chinese to reconsider their overall stance on North Korea.
"China is quite annoyed with the fact that Kim had his uncle killed," Scarlatoiu said. But he added that because "the Chinese established and helped maintain [the North] for more than 60 years, there is a traditional bond between China and North Korea."
Among regular Dandong people, like Wang Dan, neither Jang's death nor Kim Jong-un's rise to power has made any difference in how she views the country across the Yalu. When asked about human rights violations and wide-spread starvation in the DPRK, Wang had knowledge of neither.
Her husband, Wan Hui, said he knew North Korea had suffered a devastating famine in the mid-1990s, but noted that "conditions have improved significantly since then.”
So much so, in fact, that he and Wang are planning a trip to Pyongyang this fall to witness the elaborate synchronized dance and gymnastics spectacular known in the West as the 'Mass Games.'
According to Scarlatoiu, such misperceptions about conditions inside North Korea are not uncommon among ordinary Chinese.
"To many Chinese tourists, North Korea looks very much the same way China looked decades ago and some Chinese have a nostalgic view of North Korea as a remnant, a showcase of how things used to be in China," Scarlatoiu said.
Ordinary Chinese are slowly becoming aware of the real situation on the ground in North Korea and, Scarlatoiu said, “the more they know about North Korea, the more contempt they have for the North Korean regime.”
“We need to find the resources to inform the Chinese public on what is happening in North Korea and to persuade China that being an aspiring superpower is about more than economic prowess and military power,” Scarlatoiu said. “It's also about acting as a fully responsible member of the international community.”