BAMA COUNTY (Guangxi) • Plagued by headaches and numbness in his legs after a stroke, Mr Wu Weiying came to the jagged mountains of southern China in search of a cure.

Mr Wu, 66, had long heard about Bama county - brochures call it the nation's longevity capital, where illnesses vanish and people live long past 100. Eager to regain his vitality so he could play mahjong once more, he set out last September for Bama's turquoise rivers.

Here, he adopted the local lifestyle, eating mushrooms said to possess divine powers, drinking water from a river said to offer a long life, and exercising in a cave known for its pristine air. But after seven months, his condition failed to improve, and he fell into depression.

"I've lost all hope," he said, his eyes brimming with tears. "It's impossible to cure my disease."

Once a largely undisturbed hamlet hidden in the karst mountains of Guangxi province, Bama has become a magnet in recent years for China's sick and aged.

Travellers come seeking exotic medicines, bottles of "longevity water", visits with centenarians and advice on living healthier lives. Many leave after a few days feeling hopeful and rejuvenated.

But for people battling grave illnesses over the long term, the experience can be agonising. Many are drawn by promises of miracles, only to suffer setbacks. Others fall victim to scams and doctors with fake credentials.

"This is my last hope," said Ms Li Ming, 57, a retired postal worker from Shanghai, who was told by doctors last December that liver cancer would kill her within a year. "If this doesn't cure me, I'll be forced to accept my death sentence."

As the number of seniors rises rapidly in China, medical and longevity-themed tourism is blossoming. The central government, hoping to tap surging demand for eldercare, has encouraged villages across the country to refashion themselves as longevity destinations.

In Bama, once an impoverished backwater, the local government has turned centenarians into celebrities, posting their portraits on billboards and transforming their homes into shrines.

Developers are rapidly buying up land to build five-star hotels, resorts and luxury housing with names like Secret Land, marketing the properties as retirement investments for health-conscious families.

Chinese news media has promoted Bama village lore, and scientists are investigating why some residents enjoy exceptionally long lives. (A 2012 study suggested that a genetic variation might be one factor behind the phenomenon.)

Each year, more than two million people visit the county, which has a population of 270,000 and a sprightly club of 82 centenarians.

These days, tourists arrive by the busload, hailing mainly from north-eastern China, the southern provinces and Hong Kong. They bring offerings for the centenarians, asking for photographs and the secrets to a long life.

The influx of tourists has created a thriving market for dubious health products. There are endless varieties of longevity water - starting at about US$600 (S$840) a tonne - with advertisements promising an escape from illnesses such as diabetes and osteoporosis. Street vendors hawk medicinal sprays said to contain secretions from snakes and scorpions, presenting them as cures for smelly feet, menstrual cramps and arthritis.

At times, the surge in visitors has created tensions with residents, who say they are pleased by the economic benefits but worry that the tranquillity of the area has been compromised.

"It used to be quiet and pristine," said farmer Liu Sujia. "Now, it's filled with litter and ill people."

Mr Li Hongkang, who practises traditional Chinese medicine in Bama, said his list of patients had swelled in recent years. They include an actor who portrayed Mao Zedong on television, Communist Party officials, and a billionaire who brought three cars and two nurses for his ailing mother.

Mr Li said many visitors are willing to invest small fortunes in health treatments, convinced they can overcome their illnesses in Bama. Most people stay for a few days, although it is becoming increasingly popular to rent short-term residences.

"They live a lot better here," said Mr Li. "Even if they can't be cured, it's much more comfortable."

Many visitors to Bama say their health has been transformed, noting that the area is virtually free of pollution, unlike many other parts of China. They also point to a high concentration of negatively charged oxygen ions in the regional caves, which scientists say helps purify the air.

Every morning, people file into Baimo (Hundred Devils) Cave, a popular natural attraction in the county that is said to harbour special healing powers.

First to arrive are cancer patients, whose bodies have been ravaged by the disease. Then come young men battling Aids, women who have lost their hair, and children as young as 13 suffering from chronic coughs.

By midday, they are all there, perched atop cool rocks in the cave. They read spiritual texts, watch soap operas on their cellphones, and ask one another whether they believe in the cave's supposed healing powers.

Mr Chen Rangzhi, who used to manage a trading company in the southern city of Changsha, described the area as "magical". He learnt in 2013 that he had lung cancer, but stayed healthy, he said, by doing taiji exercises inside the cave, and adopting a diet heavy in boiled pigeon and apples.

Mr Chen, 62, recently counselled a group of visitors at the cave, advising them to eat dates and drink a glass of hot water every morning. He said many people believed wrongly that they could overcome their illnesses just by visiting Bama.

"This place is for nursing your health," he said. "If the hospital tells you there's no cure, then even if you come here, there's still no cure."

Outside the cave, in an area filled with butterflies and snakewood trees that is known as the "oxygen bar" because of the quality of its air, Ms Sun Luyao, 21, watched over her 72-year-old grandmother, who has lung cancer. Nearby, dozens of seniors soaked in the sunlight.

Ms Sun, who is from the north-eastern city of Harbin, said she is worried that the cave has been overrun by tourists and is starting to lose its healing power.

"If too many people come here, then the good oxygen here will be sucked out," she said.

For those whose health does not improve, the move to Bama can be draining and disappointing.

Mr Wu, formerly a supervisor at a plant that makes baijiu, a clear Chinese liquor, had a devastating stroke four years ago. He walks around Bama with a wooden cane, feeling dizzy and struggling to understand people.

Every morning, he takes part in what are called life-revival exercises. On the banks of the Panyang River, he throws his arms into the air, twists his waist and slaps his thighs, repeating lines of encouragement along the way ("Surprise yourself! Try harder!").

But he still struggles to walk long distances, manage daily tasks or hold a conversation. His wife said she has grown tired of living in an area with so many sick people.

Mr Wu said he has given up on Bama, and plans to return to his home town in the north-western province of Gansu next month.

"As long as I can manage my own life and not bother other people, I'll be fine," he said. "I just want to be healthy."

NYTIMES