A powder magazine, several cannons and the foundation of the fort's wall remain.
The main attraction today is the excellent view of the surrounding harbor.
The fort is named after King James II of England.
In 1773, the fort was armed with 36 guns, and had a barracks which accommodated 75 men.
In the 19th century, a gun fired salutes at visiting warships, as well as signals at sunrise and sunset.