“When we managed to get on a train in the south, one of my nephews froze to death so we had to bury him in the mountain and keep fleeing,” said Yoon Il-young. He was just 10 when he and his mother defected from North Korea.
As the eyes of the world are on the surprise visit of North Korea's leader Kim Jong-un to China, his first known overseas visit since taking office in 2011, there are hopes for a further thawing in relations with South Korea. With denuclearisation on the discussion table and a summit between the two countries confirmed, thousands of divided Korean families will be watching developments closely.
It was a very cold early morning in March 1947 when Mr Yoon left, assisted by domestic help. He and is mother were the last of their family members to leave the country.
“To convince my siblings to come back to the North, the communist regime detained my mother for seven days for no reason and again for 15 days, as well as my cousin. We had to go through a lot of suffering,” he said.
From 1910 to 1945, Japan was the colonial ruler of Korea. But with the defeat of the Japanese army came a power vacuum and the Soviet army took over the north part of the Korean peninsula, before the US called for negotiations. The result was a division of the Korean peninsula half way, through the 38th parallel.
The north became communist while the US army was deployed in the south. And although the period marked the end of the second world war, the circumstances were seen as tragic for the Korean population.
The separation of Korean families was gradual. The Korean war started in June 1950 and lasted until July 1953, causing millions of deaths. After the war, the demilitarised zone was created and the family separations were complete as no one was allowed to cross the border. With weak communication channels, once a family was separated, it was deemed forever.
More than 30,000 North Koreans have defected to the South.
Mr Yoon was born in 1937 in North Korea, near the border in an unrestored part of the Gyeonggi Province.
“I am the youngest of 10 siblings and I lost my father when I was very young,” he said.
"It only took two to three hours to cross the border. My hometown was very close to the demarcation line so, from the barbed wire at the demilitarised zone, you can see it, although there are no longer any houses."
His family settled in the Gimcheon area, in the North Gyeongsang Province. But as the sole breadwinner, Mr Yoon had to provide for his mother, three older sisters and two nephews when he was only 15.
"I sold rolled rice and rice cakes and I made a lot of money so I opened a small store," he said.
But he had a strong aspiration to continue studying so he moved to Seoul where he graduated from the College of Law at Sungkyunkwan University, one of the most prestigious in South Korea.
Mr Yoon is now the chairman of the Korean Assembly for Reunion of Ten Million Separated Families, where he helps those in similar situations find their lost homes and families.
“I look for the welfare of these people and provide scholarships for second to fourth generation descendants who lost their homes,” he said.
“My older brother went back to the North during the war when he was conscripted by the army, but I still don’t know whether he is alive or not as we never heard back from him.”
"I applied for a reunion of separated families for myself but was never successful."
Mr Yoon, who is now married with three children, said he is not interested in ever going back himself. "There is no reason for me to go back because I was sick and tired of the hardships we had to go through when we were there."
Jang Man-soon is a volunteer for the Assembly, and has been for the past four decades.
"My father was a farmer and the eldest of six siblings," he said. "When the war broke out, he came to the South wishing to avoid the devastation. He thought the war would end soon, but couldn't go back to our hometown after the separation of the two Koreas."
Mr Jang learnt about his father's hardships at a young age and in his early 20s began working for the organisation to help the community of people who had lost their homes in the North.
He said the lives of separated families were "20 times harder" than those who had homes in the South because they had left everything they owned and had to start from scratch.
“My father was the only breadwinner and he had to make money by selling rice and bituminous coal to support his siblings and seven children,” Mr Jang said.
“Can you imagine only one breadwinner for all those people? The suffering my father went through is unspeakable.
"Without the sacrifice or determination of my parents, I wouldn't be living a successful life."
Mr Jang, who is now 59, has a PhD in economics from Dankook University in South Korea, where he now teaches. He works tirelessly towards helping the North Korean cause.
“I feel so desperate because I’ve been working for more than four decades here and most first generation families are old so that every year I see some of them pass away,” he said.
"They only have a limited time to ever realise their dream of going back to their hometown. It's their biggest wish to go back once in their lifetime and meet any relatives that are still alive."
Every year, he visits the United Nations Human Rights Council in Geneva to tell their tales of separation. He also appealed to the UN secretary-general about the kind of realities such families have to endure.
"We're working very hard to make those wishes come true," he said. "I know the sufferings and the resentment that these people feel."
His personal hope is to bring his deceased parents to their hometown as they are now buried on a mountain overlooking it.
“If you don’t have the wish in your mind, it will never happen so it’s important.”