Bama County in Guangxi recently became famous because of its many centenarians. Its residents have a reputation for longevity. For this reason, Bama has been studied by geriatricians nationwide.
News 163.com claims because of a local high level of negative oxygen ions in the air and water rich in minerals, the average life expectancy is the highest in the world. Now the caves around the area are frequented by cancer patients and patients with chronic diseases.
They hope the cool air of the caves gives them health benefits. Others believe the area has a strong geomagnetic field. Health tourism is increasing in the area at exponential rates. 640,000 people came here just in the first five months of 2013.
Here you can find an interesting report by The Guardian.