Hacking a modern air base out of one of the most remote corners of Australia was a feat of sheer engineering will. The work fell mainly to the 17th Construction Squadron of the Royal Australian Engineers, in what is believed to have been the largest single project the corps had ever undertaken. They poured runways and taxiways into country where the wet season can dump rain by the bucketload — the wettest day on record here saw 366.8 millimetres fall in a single day in January 2013. When it was finished, Prime Minister John Howard opened the base on 5 August 1998, and named it for Air Chief Marshal Sir Frederick Scherger, who led the RAAF as Chief of the Air Staff and went on to become the nation's most senior military officer.

The logic of a bare base is counterintuitive: build everything, then leave it empty. Scherger's caretaker crew keeps the runway serviceable, the fuel systems sound, and the buildings from rotting back into the bush — and little else. The base earns its keep during major exercises, when it suddenly fills with aircraft and personnel for war games like Pitch Black and Kakadu. Then the tent lines spring up, the apron fills with grey jets, and a thousand boots churn the dust before, just as quickly, everyone leaves and the silence returns. It is a strategic insurance policy written in concrete: forward infrastructure positioned exactly where Australia would need to project air power, sitting quietly until the moment arrives.

Scherger's loneliness is precisely the point. It belongs to a trio of "bare bases" strung across Australia's vast, thinly populated north — Scherger near Weipa, Curtin near Derby, and Learmonth near Exmouth in Western Australia — built through the 1980s and 1990s under the Defence of Australia policy. The thinking was geographic. The major northern bases at Darwin and Learmonth sit some 2,000 kilometres apart, far too distant to cover the enormous arc of coastline between them. Scherger plugs a gap on the Cape York flank, a forward airfield ready to project air power over the Coral Sea and the approaches to the continent's north-eastern corner. Empty most of the year, it is nonetheless a deliberate piece of the puzzle of defending a country with more coastline than almost any nation on Earth and very few people to watch it.

For a few years, Scherger served a purpose its builders never imagined. In October 2010, with Australia's immigration detention network overflowing, the government opened the Scherger Immigration Detention Centre on the base. It held single adult men who had arrived seeking asylum — up to 300 at first, with capacity for nearly 600. A remote military airfield, chosen precisely for its isolation, became one of the most far-flung places in the country to hold people whose only crime was where they came from. The centre closed in 2014, and Scherger returned to its watchful quiet. The episode remains a reminder that this empty-looking runway has carried real human stories through its gates.