When it comes to choosing a summer camp to send your children to, North Korea may not be top of the list. But for decades the Songdowon International Children's Camp has entertained young people from around the world with its swimming pools, waterslides and boating lakes.

When it opened in the 1960s, Songdowon International Children's Camp was a centre for the kind of cultural exchanges common amongst Communist countries at the time. Set on a beach front, amongst a sweep of pine trees, it was a place where young people from friendly nations could meet.

Nineteen-year-old Valentina Boltacheva, from a town near Vladivostok in the far east of Russia, visited when she was 14. She took part in a competition run by the local government, for employees of the factory where her mother worked. The prize? Holiday coupons to Songdowon.

Image caption Details from a brochure for Songdowon International Children's Camp published in 1989 Image caption Pictures courtesy of Retro DPRK and Koryo Canada previous slide next slide

Valentina answered questions about the history of her mother's aircraft manufacturing factory and about North Korea, which she researched in her local library. She was successful, and became one of the 30 children chosen to visit - her first trip abroad.

"I thought North Korea was a hospitable country," she says. "We were well received, we always had entertainment and we were well treated. And people in general are very friendly."

The camp, with its white concrete buildings and wide, colourful waterslide, is open during the summer for North Korean children who achieve particularly good school grades. It also hosts foreign students for two to three weeks each July. Camp organisers lay on activities such as camping, morning exercises, and visits to amusement parks.

Image caption Valentina Boltacheva is top row, third from right

Foreign students are obliged to put on a cultural performance. Valentina's group chose a Russian folk dance. The boys and girls put on a polished performance in matching costumes as the audience clapped along. The performance has an old-fashioned innocence about it - like something from another era.

Tourism in North Korea More than 3,500 Westerners visit North Korea every year

A typical five-night visit costs $1,520 (£1,000)

Visits are arranged through specialist tour agencies

The capital, Pyongyang, is the most popular destination

Popular food dishes include cold noodles, cuttlefish and pickled cabbage

Most of the country's tourism comes from neighbouring China

Many of the North Korean children at the camp when Valentina visited were members of the Young Pioneer Corps - a political organisation for the under-15s. Portraits of North Korea's leaders were everywhere, and politics was never far away. "On the streets we saw the pioneers, in every room we went at the hotel at the camp there were portraits of Kim Il-sung and Kim Jong-il," says Boltacheva.

"The people are very patriotic, almost every day we saw people go to memorials and monuments to lay flowers and sing patriotic songs. It was very unusual for me."

There was plenty of food. "It was partially Korean, such as different vegetables with national sauces," says Valentina. But alongside the boiled onions, cabbage and rice were fried eggs, ham and even ice-creams and cheesecakes for dessert.

"I can say that though the dishes were national they were tasty - I didn't feel hungry."

Image caption Valentina and her group were taken to an amusement park

Living accommodation was segregated, with foreign students kept apart from locals. But Valentina says she was not aware of any awkwardness and was able to make two North Korean friends who spoke English and a little bit of Russian.

"They wanted us to call them Tom and Jerry so I don't know their real names. We had fun and went boating. We talked about things like family, sports, culture. We also talked about education in different countries."

That was five years ago. Now it seems the Songdowon Camp is struggling to fill beds.

Image caption North Korean leader Kim Jong-un visits Songdowon children's camp

Matthew Reichel, co-founder of the Pyongyang Project, a Canadian non-profit organisation promoting cultural exchange with North Korea, says he sympathises with the camp organisers - many of whom he knows well - as they gear up to attempt the difficult annual task of convincing foreign students to visit.

North Korea in the Magazine Where the football crowds are silent: "Every seat was taken and row upon row of men sat silently, wearing identical dark suits and red ties." Where the favourite treats are Choco pies: "North Koreans are not nearly as isolated as we tend to think they are." Where people want new experiences, including new music: "North Korean musicians are desperate for repertoire. The whole of 20th Century music is unknown territory."

"The camp has to be international - it is part of the reason why it was created. It would be a failure of purpose if it didn't draw foreign students," says Reichel.

He says the organisers offer scholarship programmes, and reduced fees, to entice students from Mongolia, Russia, Vietnam, and as far afield as Tanzania. But it is getting harder. "Every year they have to go out and sell the camp," he says. "And it's becoming a more difficult sell."

The problem is the majority of students come from China. And, although the camp is cheap, says Reichel - a two week stay costs around $300 (£197) - North Korea is no longer a destination of choice for many Chinese tourists.

"Chinese people are getting more picky as to where they want to go - they are interested in Europe, Canada, the States… and South Korea is doing summer camps for children - so there's a lot of competition," he says.

It's a challenge that North Korea's leaders are apparently tackling head on. Supreme Leader Kim Jong-un has plans to transform the nearby industrial port of Wonsan into a world class luxury resort, according to South Korean newspaper The JoongAng Daily.

Reichel says this area is a natural choice. "There's the beach, and the setting, beautiful mountains, and they're interested in taking advantage of all that."

He acknowledges that North Korea's natural beauty isn't the first thing that comes to mind for the few Western tourists who visit - most of whom are interested in the country's political system. And, at a four-hour drive from Pyongyang, Wonsan is not easily accessible.

As for Valentina, it seems that North Korea no longer tops her list of holiday destinations.

"I dream of visiting European countries," she says.

Valentina Boltacheva spoke to World Update on the BBC World Service. Listen back via BBC iPlayer Radio, or download a podcast.