The fort is situated on a hill, so it is positioned to oversee the trade traffic in the strait between Ternate, Halmahera and Tidore. Moreover, the Sultanate of Ternate also can be easily controlled from this fortress. This castle is unique shape, asymmetrical because it follows the contour of the hill there. Tend rounded shape with two bastions in front and a corridor along approximately 20 meters to the rear of the second bastion. When viewed from above, the shape of the fort is similar to the male genitalia.
One of the fort built by Francisco Serrao are Fort St. Lucas in 1540. The fort is located in the east, facing the island of Halmahera. The fort is also located in the north of the Sultanate of Ternate, whose function is to monitor the movements of the Sultanate of Ternate.
When Malacca fell to the Portuguese , Alfonso d’ Albuquerque ordered Francisco Serrao to sail to the east to find a local herb. Francisco Serrao finally landed in Ternate in 1512 and the era of Portuguese in Maluku spice trade began. Francisco Serrao decided to settle in Ternate. He also married a Javanese woman and built a fort.
When Portuguese resigned from Ternate being sent by Sultan Babullah in 1575, the Dutch come and take over this castle. This fort was later renovated in 1610 by Pieter Both and renamed Fort Hollandia. Then after falling into the hands of the Sultanate of Ternate, the fort was later renamed Fort Tolukko, which according to some accounts, taking the name of the ruler of Ternate named Kaicil Tolukko.