The island of Mljet is located in the Dubrovnik-Neretva County and is one of the Southern Dalmatia islands. The National Park spans between 17°19’19” and 17°26’43” of east geographic longitude and 42°45’55” and 42°48’23” of north geographic latitude. It has a NW – SE orientation, parallel along the eastern half of the Pelješac peninsula, separated from Mljet by the 8 km wide Mljet Canal.

The island has a Mediterranean climate with dry and warm summers and mild winters with a significant amount of rainfall. There are two climate periods on Mljet, one colder in winter and fall, and the other warmer in spring and summer. Regarding wind, bora is frequent at Mljet as a cold wind, and sirocco is a wet wind bringing clouds and rainfall. During summer, mistral is present every day, making the summer heats easier to endure.