One is the lost Tuggerah airstrip along Lake Road, visible only sometimes today in aerial photographs. It was part of a network of NSW coastal landing strips by military aircraft flying along the eastern seaboard in the dark days of World War II.

Lake Macquarie's legendary "Cats" - Catalina flying boats from Rathmines air base - also practised "bump and go" emergency landings on Tuggerah's wartime airfield.

Similar, but buried beneath suburbia for probably 65 years, the biggest World War II secret though concerns a pocket park on Woy Woy peninsula. Only recently, this once neglected recreation space was spruced up and even renamed Runway Park in a nod to its history.

To anyone visiting, the single clue to its past is a strip of red gravel on its southern edge, aptly enough at the crossroad of Waterloo Avenue. Welcome to what's left of Woy Woy's Trafalgar Avenue airstrip. Dating from 1942, the large site once housed a military airfield with up to eight medium-size bombers hidden under camouflage nets in sandbagged, U-shaped pens, or "hideouts".

The main runway was disguised as a single-sealed road. Meanwhile, taxiways to the pens were widened local streets where all power poles were removed to allow for aircraft wing widths.

Later, as the threat of an invasion on the Australian mainland receded, the bush airfield instead became a refuelling and emergency repairs site. The entire area was fenced off and all photography forbidden for security reasons.

Trafalgar Avenue's WW II airstrip ran from north to south towards Lion Island, stretching from McMasters Avenue way down to Oxford Street, Umina.

To further help disguise the airbase, nearby holiday cottages were kept and used by RAAF personnel. Hangars and service areas were around what is now Alma Ave, at the northern end of the current Runway Park, opposite today's Umina fire station. For protection, an anti-aircraft battery was also located close by at Blackwall Mountain.

According to brilliant local Woy Woy historian Steve Spillard, the Trafalgar Avenue wartime airstrip was built by Australian Army engineers. First, they bulldozed trees before laying down a base of compacted sandstone rubble topped by the later famous red gravel. This satellite airstrip was built for the Royal Navy Fleet Air Arm as a "dispersal" aerodrome in case its main air base, Schofields at Sydney's Quakers Hill, ever came under enemy attack.

Aircraft and aircrews from visiting British aircraft carriers rotated in and out at Woy Woy during the war. Large American bombers also regularly frequented the site. One type was the American Gruman Avenger Torpedo bomber used for anti-submarine warfare. It was ideal for patrolling the coast and in case an underwater attack was made against the Hawkesbury River rail bridge.

The RAAF stopped using Woy Woy district airstrip in 1946 and it met its Waterloo, or end, with the crash landing of a Tiger Moth biplane into the roof of a house in 1950.

The disused strip was then adapted for horse races, for drag racing or by learner drivers before being sold off from 1955 and built over. Nothing remains today except the small Runway Park being the only intact part of the runway surface still surviving.

Meanwhile, Weekender reader Wal Campbell of Diamond Beach sent me a photo of his Nana standing on Woy Woy airstrip in 1949.

Another reader with particularly fond memories of the same, now lost, airstrip is Mrs Yvonne Thompson, of Brandy Hill, near Seaham. She says her life has really come full circle. The adventurous former WRAAF sergeant said as a small child she lived within sight and sound of the bush airfield during the war years.

And the impact of a kind gesture by an airman to a five-year-old girl later led her to join the RAAF and travel overseas. Ironically, now in retirement and in the flight path of the Williamtown RAAF base, she now regularly hears military aircraft fly overhead. This is part of her story.

"In 1942, I lived with my parents and two sisters in Wyalong Street at the foot of Blackwall Mountain, only a short bush trek to the airfield then being built," she says.

With only three houses in the street, she and her elder sister would spend time running barefoot through the bush.

Then one day she recalled bursting out into a clearing where several men and a couple of Clydesdale horses were removing trees and undergrowth for an airfield.

Every day from then on the duo watched progress on the airfield, right up to laying the last layer of red runway gravel.

"Although we lived (close by) I can only ever recall one aircraft ever landing on the airfield," she says.

"That occurred (I think) in 1943 with my sister and I watching a military aircraft coming in at tree-top level to land.

"Not wishing to miss any of the action, my sister and I bolted through the bush track and stood in silence and at a distance watching the aircraft come to a final stop.

"Some time later an airman came over and asked if we would like to see inside the aircraft."

They shyly did so, where the airman explained the cockpit and the aircraft's inner workings.

"A day or so later I watched as the aircraft rolled over the red gravel, lifted into the air and became just a tiny speck in a blue sky - never to be seen again," she says.

"However, the episode did not end there - the legacy of the encounter endured and in 1957 I joined the Women's Royal Australian Air Force.

"While most other 18-year-olds at that time were living rather uneventful lives I was at Williamtown learning how to use a sub-machine gun, a .303 and a .38 revolver and if the opportunity arose I was permitted to fly with a pilot in a jet fighter trainer."

After seven of the "best years" of her life, she became ineligible to serve in the WRAAF due to her marriage. Then in 1969 she moved to Malaysia with her husband and young son for a six-year posting to Butterworth Air Base.

Here, she had time to discover remote jungle villages and experience occasional danger, ranging from race riots and killings, curfews, the odd terrorist incident on the Thai Malaysian border and chasing murderous pirates on the gunboat on the high seas.

"Had there been no wartime airfield at Woy Woy, or a kind gesture from an unknown airman, I feel confident I would never have had so many memorable and rewarding life experiences. It opened up a world to me," she says.

Today from her Brandy Hill garden she sees giant Williamtown RAAF aircraft flying above, taking great pleasure in knowing that such aircraft, "unlike my service years are now being able to be both flown and crewed by women".