According to the information in the postal code database, the postal code of Hualong District of Haikou City is 570 100. The first two "May 7th" stands for Hainan Province, the third "0" stands for Haikou, the fourth "1" stands for Hualong District, and the last "00" stands for specific delivery office.
Longhua District, which belongs to Haikou City, Hainan Province, is located in the northwest of Haikou City.