Long before anyone thought to build a citadel here, the site between the two branches of the Ciliwung River served humbler purposes. Before 1669, a tavern stood on the spot -- one of those establishments that appeared wherever Dutch traders gathered in the East Indies. In 1723, a sergeant-major named Herman van Baijen rebuilt the tavern as a large country house, trading beer and trade gossip for the quieter ambitions of a gentleman's estate. The transformation did not last. By 1743, the building had become a hospital, known as the Outer Hospital because it sat beyond Batavia's city walls. For nearly eight decades, the sick and wounded were brought to these low hills inland from the coast, where the elevation offered a modest defense against the malaria that ravaged the swampy lowland city. The surrounding countryside was fertile, the topsoil deep and rich, and the location in what would become the Weltevreden district -- today's Sawah Besar -- was considered one of the healthiest spots in all of Batavia.

Governor-General Johannes van den Bosch ordered the citadel built in 1837 as part of a planned defensive line running through what is now the Kebon Sirih and Menteng neighborhoods. Colonel Carel van der Wyck drew up the design: a rectangular brick fortress protected by an earth rampart, with bastions anchoring each corner. A central tower equipped with clocks, windows, and doors on all four sides served as a lookout post. The prince who laid the cornerstone and opened the finished fort was Willem Frederik Hendrik, a son of King William II of the Netherlands and one of the rare members of the Dutch royal family to actually visit the East Indies. The citadel took his name. Whether the prince appreciated the irony -- a fortress in a colony that generated wealth precisely because no one was attacking it -- history does not record.

The fort did not stand alone. Surrounding it was Wilhelmina Park, named after the queen who was inaugurated in 1898, though the park itself predated her reign. Van den Bosch had commissioned it in 1834, three years before the citadel. At 9.32 hectares, it was reportedly the largest modern park in Batavia and, some claimed, the largest modern park in all of Asia at the time. The grounds served double duty: a vegetable garden for Dutch officers and a favorite promenade for VOC officials and landlords who had settled around Weltevreden. The park stretched out in front of Jakarta Cathedral Church. Within its boundaries stood an Atjeh-Monument, erected to commemorate Dutch soldiers who had died in the brutal Aceh War. By the mid-twentieth century, both the monument and the park had become symbols of colonial power that the newly independent Indonesia had little desire to preserve.

In 1961, the demolition crews arrived. The Atjeh-Monument came down first, a few months before construction began on the structure that would replace everything -- fort, park, and colonial memory alike. President Sukarno had chosen this precise site for Indonesia's grand national mosque, Istiqlal, and the choice was deliberate. Building the country's most important Islamic monument on the ruins of a Dutch military installation was an act of architectural overwriting, a declaration that the colonial chapter was not just over but buried. The mosque took seventeen years to complete. When President Suharto inaugurated Istiqlal in 1978, the Citadel Prins Frederik had been gone for nearly two decades, its bricks carted away, its earth ramparts leveled, its clock tower dismantled. What had been a fortress guarding Dutch imperial interests became the prayer hall of a nation that had expelled the empire. The Ground Building returned to the ground.