A predetermined-area management system is configured to communicate with a communication terminal. The predetermined-area management system includes: a storage unit that stores image identification information for identifying image data and predetermined-area information for identifying a predetermined area in the image data in association with each other; a receiving unit that receives image identification information that is transmitted from the communication terminal; an extraction unit that searches the storage unit by using the image identification information received by the receiving unit so as to extract associated predetermined-area information; and a transmitting unit that transmits, to the communication terminal, the predetermined-area information extracted by the extraction unit.