By Helen Fawkes
BBC News, Solotvyno, western Ukraine
Solotvyno is not exactly a glamorous destination.
From the outside, Solotvyno mine seems an unlikely health centre
But the Soviet-looking Ukrainian mining town attracts thousands of visitors each year.
They come to this run-down area searching for a remedy buried deep underground.
The Solotvyno Salt Mine, near the Romanian border, offers speleotherapy, an alternative treatment for people with respiratory conditions.
It now hopes to attract patients from Britain, where more than five million people suffer from asthma.
At Solotvyno, patients spend several hours a day breathing in the salty air more than 300 metres (984ft) below the surface.
When you get out of the lift, which is shared with salt miners, you step into what looks like a magical kingdom.
The walls appear to be sculpted out of white ice.
Everywhere salt crystals sparkle and twinkle.
"It's beautiful, and it looks like a marble castle from a fairy tale," says Maria Congard, from Denmark, who suffers from bronchitis.
"The air is very good, so you don't have problems with your lungs down here."
The mine is said to have a unique micro-climate because of tiny salt particles in the air.
It is claimed that this helps people with breathing difficulties.
At around 22C it is also very warm underground, so most people just wander around the tunnels in their pyjamas.
This salt sanatorium specialises in helping youngsters - about half of the 200 people who get treated every day are children.
"It's easy to breathe and it's pleasant to sleep here. Nothing disturbs you," says Yaroslav Chonka, the mine's chief doctor.
"The kids who come here start running around like mice as soon as they get down into the mine."
Treatment takes place over a two or three week period.
Some people stay underground for a few hours every day, while others spend the night.
Each session costs $22 (£13).
Wearing bright green pyjamas, Roxlana colours in a picture of a princess, helped by her mum.
The seven-year-old from central Ukraine has come here because she has asthma.
"I'm not frightened about being here, why should I be? The mine is very interesting and very beautiful.
Inside, the passageways and rooms are carved from salt
"It looks like somewhere that Father Christmas would live. And it makes me cough less."
In the giant children's room, some of the youngsters play, others rest on their beds and a couple play chess.
All along the passages there are small rooms which have been carved out of salt.
There are about four patients to a room, each with a blue curtain for privacy.
This state-run salt mine was established as a treatment centre during Soviet times and most of the patients are Ukrainian.
But there has been an increase in the number coming from Europe, now that people from EU countries no longer need a visa to get into Ukraine.
"We were not allowed to promote this place, so for many years only a few people knew about us outside the USSR," says Mr Chonka, the chief doctor.
"Now we want to attract more patients from abroad - especially British people, as according to medical research they have some of the highest levels of asthma in the world."
Western doctors are sceptical of claims that salt therapy can cure respiratory problems.
But many of the patients have already been won over.
Patients are required to wear hard hats while underground
Twelve-year-old Anya is giving piggybacks to friends.
Throughout the mine you can hear children running around - something that many of them often find quite difficult.
For these youngsters just a few days or weeks free from their condition is good enough for them.
"I came here to get treated as I have severe asthma," says Anya.
"I feel great because the salt is very good for helping my condition and since I've been here I haven't had any asthma attacks."