Mindanao

Mindanao or still commonly as Southern Philippines, is the second largest island in the Philippines. Mindanao and the smaller islands surrounding it make up the island group of the same name. Located in the southern region of the archipelago, as of the 2010 census, the main island was inhabited by 20,281,545 people, while the entire Mindanao island group had an estimated total of 25,537,691 (2018) residents.
Credit: Wikipedia