Misteriosa is a Caribbean island, located south of Cuba and west of Jamaica. It is surrounded by a ring of smaller islets that force any incoming ships to sail along a narrow channel to Misteriosa's shore.
The island is dominated by a large mountain, out of which a massive Mayan temple was built sometime before the Golden Age of Piracy, before it was abandoned by its inhabitants. A small bay is situated below the temple, with a large waterfall feeding into it from the top of the cliff above. To the south, there is a smaller temple that scales a vertical wall before meeting the shore.
While undergoing a contract from the Assassins, Edward Kenway found one of his targets had made camp in the temple and eliminated him. Marooned pirates could occasionally be found in the bay and rescued. Later on, Kenway met on Misteriosa with Bartholomew Roberts, a Sage and reincarnation of Aita, before the two formed a partnership to recover a shipment of blood vials from the Portuguese Navy.