Otanaha Fortress is a historic fort in Gorontalo which have been built in the 15th century although at this time no longer intact as before. Otanaha Fortress is located in the Village Dembe I, Kota Barat sub-district, Gorontalo. Based on many resources, Otanaha fort was built in 1522 by King Ilato. The fort was built on the initiative of the Portuguese master of the ship docked at the Port of Gorontalo. The initial goal was as defense and security of the nation from attack. According to some sources, the fort was only built from a mixture of sand and limestone. while the adhesive comes from the egg Maleo. This fort actually has three names in three of fortress, which Ulupahu, Otahiya, and Otanaha. But it is more popularly known as Otanaha Fort.