For most Australians the Second World War feels like something that happened overseas. For North Queensland it arrived at the coastline. After Japan's declaration of war in December 1941, and the bombing of Darwin in February 1942 and Townsville that July, the northern coast suddenly became a front line. When the fighting moved into New Guinea in mid-1942, the region turned into a vast staging area, full of American and Australian troops moving north. Radar was the early-warning skin stretched along that coast. The RAAF built around twenty radar stations down the North Queensland shore, each meant to catch approaching aircraft while there was still time to scramble fighters or sound an alarm. No. 211 Radar Station went up on Charlie's Hill late in 1943.

Most of those coastal stations were mobile or makeshift. Charlie's Hill was different. It was a 200-series fixed-ground "high flying" station, one of only two of its type in North Queensland, the other being No. 220 at Bones Knob near Tolga. It ran British Advanced Chain Overseas equipment in the high-frequency band at 42.05 megacycles per second, a wavelength of about seven metres, and it could measure not just the bearing of an aircraft but its height. Two timber towers, 186 feet tall and shipped in kit form, stood about a hundred metres apart carrying the transmitting and receiving aerials. The delicate electronics lived in two bomb-proof igloos of reinforced concrete, set roughly eighty metres apart on the summit, one for receiving and one for transmitting.

A radar station is only as good as the people watching the screen, and the unit here was small, around thirty-five in all. The station ran 24 hours a day in three shifts. Each shift was just three or four people: one operating the set, one at the plotting table, one recording the messages coming in, and one working the telephone. To break the monotony of staring at a glowing trace, they rotated jobs every two hours. The work was shared between RAAF airmen, who lived on site, and members of the Women's Auxiliary Australian Air Force, who served as operators, plotters and recorders. The WAAAF women worked the daylight shifts and were billeted in the hotel down in Home Hill, cycling or being driven up to the hill and back.

The two igloos were cleverly built for a place that expected to be bombed. Each is a low, semi-circular vault of reinforced concrete, about ten metres long and six wide, with a short tower at one end. The towers doubled as ventilation: fans drew fresh air in through the front and exhausted it up the tower, no small thing in tropical heat with equipment running constantly. The receiving igloo's doorway was staggered like an S-bend, so that someone could walk in and out without any light spilling from inside to betray the position at night, while the same baffled entry kept air flowing through. The transmitting igloo still shows the holes in its concrete floor where the aerial cables ran out to the towers. A camp of huts, mess and toilets, and a diesel generator sat at the base of the hill on the northwestern side.

Japan surrendered in August 1945, and the North Queensland defences were stood down. Charlie's Hill stopped operating on 1 October 1945, its equipment dismantled and carried away. Before they left, the officers and operators threw a thank-you for the people of Home Hill: a tennis afternoon, then dinner and a dance in town, a small grace note at the end of a hard posting. What remains is unusually complete. Both concrete igloos still stand, along with two spotter's posts, chest-high concrete-lined holes where Voluntary Air Observers' Corps members confirmed radar contacts by eye, and the square footings of both timber towers. The Burdekin community has looked after the site as a quiet, view-rich memorial to a coast that once held its breath.