I can't believe how much the landscape has changed - almost a 100 years ago it was completely devoid of vegetation. Today, it's heavily forested and unexpectedly harbours one of our territory's more unusual historic sites, a place where the more you dig, the more you discover its secret past.

In fact, until September this year, when reader Hilary Wardhaugh submitted a photo of the shallow concrete "reservoir" she stumbled on while exploring this rare pocket of undeveloped land on the fringes of Fyshwick, I was completely unaware of the hill, let alone it's remarkable history. Now, in the space of just a few months, I've become obsessed with uncovering its intriguing past.

Surprisingly, I'm not the first to be preoccupied with "Radio Hill" as it's unofficially known. Ardent Canberra historian Alan Foskett who first "discovered" the reservoir in 2005 has published not one, but two books which delve into the area's unusual past.

"The Radio Hill Reservoir water was the first major use of the original Cotter Dam and pumping station," explains Foskett, who adds, "the water was pumped from the Cotter to a reservoir atop Red Hill and then reticulated to Radio Hill and on to the Molonglo Internment Camp and later workers' settlement."

Internment camp? Yes, you read correctly. Towards the end of World War I, Australia responded to a request by Britain to house 3500 German and Austrian nationals held in China by building an internment camp in the area now known as Fyshwick. The camp was hastily built in just three months, however, the original 3500 internees never arrived, and instead, 160 German and Austrian nationals were brought from other camps in NSW.

"The camp was closed at the end of 1919 and the reservoir is the only remaining evidence of the camp and the subsequent workers' settlement," Alan explains.

About 17 years after the war, the Fyshwick hill was once again in the spotlight, playing a pivotal role in the pioneering days of commercial aviation in Australia.

In 1935, when Holyman Airways planned a commercial service between Melbourne, Canberra and Sydney one of the conditions of its licence was that it needed to have radio communications for the entire flight. This requirement was a result of the "Southern Cloud disaster" in 1931, when an Avro X aircraft crashed in the Snowy Mountains en route to Melbourne. Just after takeoff the weather forecast changed to cyclonic conditions but the pilot of the Southern Cloud was unable to receive the updated forecast as he had no radio contact. (Out of the Clouds, July 5, 2013).

Although Holyman Airways was able to employ the services of a maritime station in both Sydney (VML) and in Melbourne (VIS), the lack of a radio station in Canberra meant that its plans for the route were likely to be thwarted.

Fortunately for Holyman, at a similar time, Canberra commercial radio station 2CA moved its studio and transmitter from the back of a Kingston shop to Radio Hill, which just so happened to also be close to Canberra Airport.

An arrangement was promptly forged between Holyman and 2CA, whose owner, Jack Ryan, was also a flying enthusiast, and this week I tracked down Jack's then right-hand man at 2CA, George Barlin. With all the zeal as if he'd done it yesterday the charismatic 98-year-old recalled the novel way he "talked down the planes into Canberra Airport" almost 80 years ago.

"The Holyman aircraft, a de Havilland Dragon 8-seater, installed a receiver for 2CA and we built a receiver for the aircraft frequency so we could communicate with them," explains Barlin, who remembers clearly, "the plane left Sydney at 7am and once it got over about Wingello [the Southern Highlands], they'd call us on Morse code and we'd answer on Morse and then as it flew closer we could talk to the pilot and he could talk to us."

Despite 2CA not broadcasting any programs during the arrival times of the plane into Canberra (in the mid-1930s 2CA had programming for only a short time around the middle of the day and also during evenings), many listeners tuned in just to hear George talk the plane in. "While anyone tuned into 2CA couldn't hear the pilot, they could hear everything I was saying to him," George explains.

One of those listening to George's voice cutting in among otherwise long stretches of dead air was "Mrs Barton who had a hire car company in Canberra". "She got all the information about potential customers just the same as everyone else listening to 2CA," George explains.

The landing procedure was astonishingly simple. "I'd tell the pilot when he was directly overhead the station, he'd then head toward Tharwa, do a U-turn and touch down," explains George, who with no weather instruments also had to estimate the wind direction, speed and visibility. "It really was a case of wetting the index finger and sticking it out the window of the studio," Barlin says.

However, it got a little more complex when it was foggy. "In those days there were no trees on Radio Hill and we had a direct line of sight to Mount Ainslie which we knew was about 1000 feet above the airport," explains George, who adds, "there was a quarry about halfway up on its southern side [still there, but disused], so we knew it was about 500 feet above the airport, and we used it as a reference to estimate the height of the fog."

"On especially extra foggy mornings, I'd be waiting outside the station to let the pilot know when he was right over the top of me, but often I couldn't hear anything, and was left wondering where he was ... and then the phone would ring and one of our listeners would report that he was flying over their house in Hall or somewhere else in Canberra," chuckles George, who would then immediately relay the information to the pilot.

"Incredibly, we never lost a plane!" George exclaims.

Incredible indeed.

Radio Hill: Check it out for yourself. Park near Anytime Fitness in Newcastle Street (near corner with Canberra Avenue and opposite DFO) and wander (about 100 metres) through the pines trees towards the top of the hill. Take care for the area is unfortunately littered with rubbish and at this time of year there could be snakes lurking in the long grass and under fallen logs. The concrete pad of the old 2CA building is about 50 metres to the north (towards Whyalla Street) of the reservoir.

Did you know? The commandant at the Molonglo Internment Camp's and his military unit were housed in buildings located on the ridge where Fyshwick's Molonglo Mall is now located. There was also a guard tower which overlooked the camp which stretched on either side of what is now Wollongong Street, towards the Molonglo River.

Camp stories: Alan Foskett has self-published two books about the Molonglo Internment Camp. Both books, namely The Molonglo Mystery: a unique part of Canberra's history (2006) and More About Molonglo: the mystery deepens (2008) are out of print, however copies are held by the National Library, the Canberra and District Historical Society, the ACT Heritage Library and local public libraries. Details: alan.foskett@hotmail.com

Radio yarns: Canberra radio and television living legend, George Barlin details the halcyon days of 2CA, including working on Radio Hill and talking in planes to the airport in his self-published biography A Quirk of Fate (2002).

Over recent weeks this column has received a number of emails from residents of Weston Creek curious about the garish appearance of a tree stump on one of their suburb's busiest intersections.

According to Carolyn Henry, the tree stump, located on the Tuggeranong Parkway on-ramp from Cotter Road, city-bound "is often dressed to suit the occasion be it football finals, Halloween, Christmas, Easter and even spring time." Although "Stumpy" no doubt puts a smile on the face of many drivers as they head off on their daily commute, not everyone is pleased to see it as they round the corner. "I only ever seem to notice it at night and it looks extremely creepy," Tash writes.

Carolyn, who suspects "Stumpy" is a girl, wonders who her fashion adviser is, and like me, is keen to know "the story behind her birth".

Contact Tim: Email: timtheyowieman@bigpond.com or Twitter: @TimYowie or write to me c/o The Canberra Times 9 Pirie Street, Fyshwick. A selection of past columns is available at: canberratimes.com.au/act-news/by/tim-the-yowie-man

Clue: Sisterly love.

Degree of difficulty: Medium

Last week: Congratulations to Florence Young, of Macarthur, who was the first to correctly identify last week's photo, sent in by reader Chris Blunt, as the roof of the old stables building at Government House, the official residence of the Governor-General in Yarralumla. A self-confessed "fan of Canberra history and an amateur snapper of architecture", Florence recognised the location after taking a photo of almost the identical scene as that which Chris snapped at last month's Open Day at this historic property.

A number of readers including Emma Holliday, of Rivett, thought the photo was taken at Lanyon Homestead near Tharwa, while even more readers, including Mike Lester, of Kambah, mistook it for the weather vane under the bell tower at Micalago Station, Micalago.

How to enter: Email your guess along with your name and address to timtheyowieman@bigpond.com. The first email sent after 10am Saturday, November 22, with the correct answer wins a double pass to Dendy cinemas.