Located in the northwestern part of Hainan Island, Chengmai County (pop. 570,000) has a total area of 2,072km². Chengmai County was the first place in China to be recognized by the UN as a "Global Longevity Hometown". The county has a forest resource area of about 12 hectares and a forest coverage rate of over 54%. Selenium-rich soil is found in 57% of the country's total area, making it one of China's richest and largest selenium-rich soil deposits.