A map that identifies places in China where people live longer went viral on WeChat recently and was shared 100,000 times.
The map was made by the Institute of Geographic Science and Natural Resources Research of the Chinese Academy of Sciences and found where the oldest people in China lived.
The institute has been studying the relationship of geography and old age since 1968. In plotting the map, they used data from the census in 2010 and measured elements in the environment where centenarians lived.
From the data, they were able to identify the country's long-life towns and provinces. The data was published in 2015 on the Scientific Decision Making Journal.
The institute also observed that there was a higher older population by the Yangtze and Pearl River deltas. These places had a mild climate and large forests.
The data revealed that in Hainan, the population density of people above the age of 65 is higher that the global ratio.
Wang Wuyi, a researcher at the Institute of Geographic Sciences and Natural Resources Research, said, "Geography influences people's health in many ways. So-called longevity towns are an integration of genes, mental factors, the natural environment and social environment."
"The green hills, blue skies, beautiful scenery, nourishing food and a harmonious social environment are all good for long life," he added.
Similarly, a group of researchers in the U.S. found that in Ikaria, Greece, people are living longer. The group called the place as "the island where people forgot to die."
The editor-at-large of National Geographic is Dan Buettner and went on an expedition around the world to locate where to see the most number of seniors.
Buettner said that Ikaria "is an area that was largely isolated from the rest of ancient Greece and even modern Greece, and it incubated a set of lifestyles and a population that lives about eight years longer than average, with just a fraction of the average rate of dementia."