Newsround's Gavin in the salt cave
Coping with allergies and conditions like asthma can be pretty tough, but a treatment centre has opened that claims to help people get better using SALT.
For centuries people with problems to do with their lungs in other countries have been going into salt caves to help treat their conditions.
And now patients at a clinic in London are trying it out in a man-made cave.
It's thought breathing in the tiny particles of salt helps to stop people coughing and wheezing as much.
When people have something that irritates their breathing like hayfever or asthma, tubes in their lungs can become all swollen and blocked up with sticky stuff.
Gavin talks to an asthma expert
The idea behind the salt cave is that kids breathe tiny particles of salt into their lungs while they play.
The salt helps dissolve the gunge in their lungs and makes their tubes more flexible, so they don't suffer so badly from coughing and wheezing.