Monster island are 6

Area 6, is perhaps, the most extensively studied area as it is home to the Godzillasaurs, Godzilla and Minya and also to King Ceasar. Ceasar has hollowed out an immense cavern to live in. He also serves as surrogate grandfather to both of the dinosaurs. This northeast area is also home to the last Foetodon who lives in the jungle above king Ceasar's lair, though a dangerous predator, the land crocodile knows better than to try to attack Minya as Godzilla would squash the beast and thus tolerates the young monsters antics and even appears to watch out for the saurian at times. The area is flanked by the mountain to the west and the cliffs to the east.