By Roger Pinney, BBC Wales reporter
Belarus charity Chernobyl Children Lifeline arranges dozens of trips a year for children living in areas affected by the Chernobyl explosion.
Few houses have running water in the girls' village of Lipen
Olga Norka and Anghelika Mashkova, from Lipen in Belarus, recently visited north Wales as part of the programme.
Among the trippers on Dinas Dinlle beach near Caernarfon, two excited little girls throw stones into the waves.
Olga and Anghelika, both nine, are far from home, a landlocked village in Belarus which lies hundreds of miles from the nearest sea.
Belarus suffered the worst of the radioactive fall-out from Chernobyl.
Children like Olga and Anghelika are growing up with its legacy, and visits to north Wales provide an escape.
Parts of Belarus are so contaminated today that no-one is supposed to live there.
Among teenagers, rates of thyroid cancer are still abnormally high. Many suffer suppressed immune systems.
Olga says she missed her parents and her cat
Olga and Anghelika themselves are apparently healthy.
They are part of a charitable programme which brings children from Belarus to Wales for month-long visits, giving them healthcare and fresh air - although the emphasis is on having fun.
"I liked it very much there," Anghelika told me on her return to Belarus.
"We went for walks and went riding on a horse. We went to different parks. We went to the sea. We don't have all those things here."
Both girls beamed as they recalled their time in Wales. Olga says: "When we arrived we liked it very much. We went on lots of different excursions. But I missed my parents and my cat which I love a lot."
A little homesickness is to be expected so far from home.
But there is a serious side to their visit here. Health care in rural Belarus can be rudimentary. In Wales, they get eye and dental check-ups.
For the girls, life in Belarus is far removed from that of their counterparts here.
Anghelika says she liked Wales "very much"
By UK standards, it is a poor country with an economy struggling following the break-up of the Soviet Union.
Around 1,000 people live in their village, Lipen. Most adults work on the local collective farm. Few of the houses have running water, wells provide the main source for washing, cooking and drinking.
Anghelika's home, tin roofed and timber walled, is typical of the Belarussian countryside. Inside it's warm, if sparsely furnished.
Over a meal of potato pancakes and soured cream, her step-father Grigori recalled the Chernobyl accident two decades ago.
At the time he was an agriculture student in Slovgorod, nearer the Ukraine border.
"I remember there were police checkpoints everywhere and they would stop you," he says.
"At the beginning they wanted to hide what happened. But then the rains came and the rains left an orange coloured dust it was like rust. Then it became known what happened."
Anghelika's mother Irina understandably worries about her daughter's health and she's appreciative of the help she had in Wales.
"I think she's changed in the month she was away. She benefited a lot from her visit. Her teeth were checked as well as her eyesight. Its not easy to do that here," she told me.
The girls' visit to Wales was supported by the charity Chernobyl Children Lifeline.
Each year it arranges dozens of similar trips to the UK. Svetlana Povova, one of the charity's workers in Belarus has no doubt about the value of the exercise.
"They get to breathe air which hasn't been contaminated, eat uncontaminated food and drink uncontaminated water," she says.
"Not enough is known here about how what happened at Chernobyl makes our children suffer."
And this two decades on from the accident. It may be another 20 years or even longer before Belarus fully recovers when another generation of her children may be looking to Wales for help.