dont forget Badgerys creek airfield about 3 miles south of St Marys.. how many of you can find that?
Is that the one at 33 51 48 S and 150 46 27 E - called Fleurs Aerodrome.
Wikipedia says -
Fleurs Aerodrome was a parent aerodrome built on behalf of the Royal Australian Air Force near Penrith, New South Wales, Australia during World War II.
Construction started on the aerodrome in 1942 and was still under construction in 1944 as part of a proposal to base a United States Navy Fleet Air Wing in Sydney should the need arise. Initially planned with three runways, No.1 (5000ft) and No. 3 (6000ft) runways were serviceable, however construction of No. 2 runway (5000ft) was abandoned. A total of eight aircraft dispersal hideouts were constructed and accomodation was a farm house and a former Civil Constructional Corps camp.
In 1969, Fleurs was considered as a site of the second aiport for Sydney. The aerodrome is now utlised as precision ground-reflection antenna range operated by the University of Sydney, known as the Fleurs Radio Obervatory.