[2] All the Australian states contributed the funds to build the fortress, and the British Government provided the guns.

In 1956, with the advent of the missile era, all coastal defenses were made redundant and closed, including Princess Royal.

The buildings were alternatively used as school rooms, migrant hostels and then holiday camps,[2] by the 1970s the site was abandoned and succumbed to vandalism.

[6] Eventually the site became a museum; within the fortress grounds are restored military equipment including shore batteries, armories, barracks, the 10th Light Horse display, trails and a collection of naval guns and torpedoes.

The Military Institute, Guard House, Barracks and Repository Store are situated around the parade ground, whereas the location of the other buildings depends more on the site topography.

[14] By September 2016, the centre was ranked as Australia's number one museum by TripAdvisor users and had attracted 136,000 visitors since opening.