Once there, she was given asylum by South Korea and is now part of a group of refugees telling their harrowing stories for the first time

Sharon traveled more than 2,300 miles across China and Laos to Thailand

A 23-year-old woman condemned to a life working down North Korea's coal mines for 15 hours a day has revealed how she faced crocodiles, dodged human traffickers and climbed across mountains during her two-month flight to safety.

Sharon Jang trekked for more than 2,300 miles – a distance further than the entire length of Europe - to escape the secretive state.

To do so, she had to cross through two of North Korea's closest allies, China and Laos.

Scroll down for video

Brave: Sharon Jang traveled for two months to reach Thailand after escaping North Korea, where she had been forced to work in a coal mine, like her grandfather and mother before her

Life sentence: Had she been caught, she risked being imprisoned in one of the secretive state's camps - where, according to the UN, conditions are akin to those for the captives of Nazi Germany in the war

Dictatorship: Kim Jong Un, who has led the country since his father's death, is known for his harsh punishments. Reports of people being executed by anti-aircraft guns have surfaced recently

Had they caught her, she would have been returned and incarcerated in one Kim Jong-Un's prison camps, where conditions are said to be akin to those suffered by captives under the Nazi regime.

But Sharon, who was barely out of her teens when she undertook a journey many are too terrified to even contemplate, succeeded in reaching Thailand, and the South Korean embassy.

And now she has joined thousands of other defectors in Seoul, where for the first time since she fled in 2011, she and two others have revealed exclusively to MailOnline details of their dramatic escapes - and the appalling cruelty which led them to risk such a journey.

Sharon's misfortune began years before she was born, when her grandfather's status as a South Korean captured during the Korean War cast suspicion over the entire family for generations.

For her, there was never going to be any question of going to university. Instead, like her grandfather and mother before her, she was ended up working for up to 15 hours a day in a coal mine near the Chinese border.

The fate of her family was preordained by the government, she says, in line with a heredity class system known as 'songbun'.

'My grandfather was repatriated and worked in the coal mines. In North Korea, that's not good work of course,' explained Sharon.

'As that work passed down the generations, my mother and her family all worked in the coal mines. My mother met my father while working in the coal mines and I was born.'

North Koreans today can buy their way out of their set family history, but as she had no money, she effectively had no choice but to work in the mines like her family.

It is hard to believe this petite young woman, dressed in a pretty summer dress, could have spent three years lugging bags of coal up and down ladders at Hakpo coal pit.

'I don't know how many kilos it was (I had to carry). It just felt heavy,' Sharon said.

Sharon began work aged just 17 at the mine, located just several miles from the infamous Hoeryong concentration camp, or Camp 22.

If she ever needed a reminder of just how dangerous disobeying orders from Pyongyang is, she needed look little further.

Those locked up in Camp 22 - said the be the most 'dangerous' of political prisoners, including Christians and people returning from Japan - are never released.

A former guard revealed how they were walking skeletons barely treated as human, who his colleagues sometimes beat so severely their eyeballs fell out.

Domination: The control exerted by the state, and fear of the camps, cannot be underestimated

Horrendous: This drawing by a former North Korean prison guard of torture at a camp is describing a position called 'pigeon torture'. where 'prisoners are reportedly beaten on the chest until they vomit blood'

Everyday torture: One of the drawings by the guards, simply titled 'Detention centre' seems to depict a guard forcing a prisoner into a small opening in a wall

Death sentence: This picture by a guard is entitled 'The corpses are taken to the crematorium'

Flight: The mine where Sharon was forced to work was near to the Hoeryong concentration camp, in the north of the country. To escape, she traveled through China and Laos to Thailand - a distance of thousands of miles

In comparison, Sharon's life in the coalmine was far easier. But then again, conditions in North Korea's coalmines sound, if anything, worse than those faced by miners in Victorian Britain.

A typical day lasted from 7.30am until 9.30pm and, despite working in hazardous conditions, Sharon says workers were expected to buy their own safety equipment with their measly monthly salary of just 3,000 won, equivalent to about £15.

'The air isn't good and water gets into your shoes, but you just go in,' she said. 'Because I had no money, I couldn't wear boots.'

Her escape came when her mother fled the country, and then paid a broker to arrange for her daughter to follow her.

'She said there would be more things for me that I wanted to do if I came here,' said Sharon, who now dreams of becoming a nurse. 'I also missed my mother and thought if I came here I'd be able to follow my dreams.'

Like most defectors, she says she travelled through China and Laos to reach Thailand, where North Koreans can apply for asylum at the South Korean embassy in Bangkok. Detection in communist China or Laos would end in repatriation to North Korea, where imprisonment or worse can await those seen as disloyal to the regime of Kim Jong-un.

Terrifying: 'I was afraid of being caught,' Sharon told MailOnline this week, four years after her escape

Determined: This young woman once contended with crocodiles as she crossed a continent

'The most difficult thing was the danger,' she said of her perilous trek that saw her cross mountains and the crocodile-infested Mekong River. 'I was afraid of being caught.'

Today, Sharon is one of a number of defectors who are telling their stories with the help of Teach North Korean Refugees, a Seoul-based volunteer group founded by American Casey Lartigue and South Korean Lee Eun-koo.

HOW THE TIDE IS CHANGING FOR NORTH KOREA'S DEFECTORS People who dare to leave North Korea have always known they were Those who are caught can be executed, or sentenced to life in prison. The best they were able to hope for for more than half a century was a five year sentence. Even so, it is thought up to 300,000 have fled since shortly after Kim's grandfather Kim Il-Sung took control of the country. But there is a change in the air. Not all those who return, or who are caught, are sent to the notorious prison camps. There are even reports of him offering money for returnees as far back as 2013. Border control has been tightened, but Kim has now launched a new propaganda war against the lifestyle to be found in the south. He has even enlisted former defectors to speak out about the 'horrors' of the capitalist society they found after leaving North Korea. In 2012, one woman apologised at a televised press conference in Pyongyang for betraying her motherland and thanked Kim for bringing her under his 'profound loving care' while another dubbed South Korea a 's****y world with no love'. Additional reporting: Reuters Advertisement

Refugees join not only to learn English for personal and professional reasons, but also to gain the confidence to speak out about their experiences in one of the most isolated countries in the world.

Harrowing stories of life in North Korea and dramatic accounts of escape are common among those who attend.

Revealing her story in public for the first time on a recent Saturday in Seoul, another female defector told a small audience about living through the North Korean famine of the 1990s.

But her journey to freedom was beset by the horrors Sharon was able to avoid.

Indeed, while the trek took Sharon just two months, it would take Jenny, as the defector wants to be known, seven years to reach the safety of Seoul after fleeing her native Yonsa County in 2001 with her mother and younger sister in order to escape hunger and deprivation.

'Here in South Korea, food is everywhere. But in North Korea I suffered,' she said, breaking down in tears several times.

'For years, I usually ate only once a day. It was a living hell.'

Estimates for the number of people who starved to death vary widely, from around 500,000 to as many as 3.5million.

The defector, who is still so terrified of Kim's regime she refuses to have her photo taken, added: 'You may never know the pain of watching someone die before your eyes. I saw it several times.'

But their troubles continued as soon as they crossed the border into China.

'I hid in the mountains and fields,' she said. 'My mom and I got caught and sold by human traffickers. We worked like slaves.'

She says she spent the next three years being forced to work on a farm, often enduring physical and verbal abuse.

Ingrained: This defector - known as 'Ken' - was too scared to show his face, but revealed how he had escaped North Korea by swimming across an icy river to China, before making it to Seoul, in South Korea

Service: Ken (not pictured) was part of the military for 10 years - but was unable to get a good job because his mother and brother had already defected. In the end, he felt he had little choice but to go as well

Eventually, she escaped and, after spending several more years working illegally in China, made her way through Myanmar, Vietnam, Cambodia, Laos and Thailand, from which she arrived in South Korea in 2008.

But even those who have worked hard to prove their loyalty to the Kim family have their own stories of hardship.

The famine in North Korea may be over, but poverty and hunger remains rife. More than a quarter of North Korean children are chronically malnourished, according to U.N. data, and the country's economy is roughly one fortieth the size of South Korea.

And serving in the military was no guarantee of a meal at the end of the day.

One former soldier - another of the defectors who gather together in Seoul - describes being constantly hungry during his 10 years of military service, which finished in 2010.

The man, who goes by 'Ken' and doesn't want his face shown out of fear for his safety, says his meals in the army often consisted of little more than a small cup of rice and pickled radish.

He told MailOnline: 'They provide food officially every time, but not enough. So that's why some North Korean soliders go out to civilian areas to take people's property, only to survive.'

Originally loyal to the Kim regime, he says he lost faith in the government after he was rejected for membership of the Workers' Party of (North) Korea, a prerequisite to a good job in the country.

Despite years in the military, the earlier defection of his mother and brother left him blacklisted from work.

'I was always rejected because my mother and brother were missing,' he said. 'I could not even get a job that had much lower requirements than my skills and qualifications.'

Regime: The Kim family have ruled the country since Kim il-Sung (centre, with his son and successor Kim Jong-Il) took power in 1948. The first defections happened in the early 1950s, it is thought

Changing: Both current leader Kim Jong Un's father (pictured together) and grandfather took a harsh view of defectors - but Kim is taking a different, softer line to entice people back

With little opportunity to make a living, he finally decided to join his family and escape the country.

'My loyalty would never be rewarded,' he said. 'The Kim family does not care about their people. They only care about power.'

So in the winter of 2010, Ken swam the icy waters of the Yalu River into China, meeting with a broker who would help transport him to Thailand.

In Laos, he says he twice barely escaped detection, a fear so great he carried pills with him to overdose if necessary.

On one occasion, he says he and several other defectors were questioned by police at a border checkpoint. Unable to understand their language, he simply answered 'no' to everything he was asked.

'Finally they decided to let us go. It was a very incredible experience,' he said. 'When I was in North Korea, I never thought about whether God exists or not. But God answered two times.'