There appear to be circles on the ground indicating something is buried. These patterns are common near Military instalations, though we do not know the significance yet.

Summary
Airport type:  Military
Operator:  Aust. Army
Location:  Sydney, New South Wales
Elevation: AMSL  250 ft / 82 m
Runways
Direction  Length  ft  m Surface
11  360  118  Asphalt
29  600  197  Asphalt

Holsworthy Barracks is located in the outer south-western Sydney suburb of Holsworthy. It is part of the Holsworthy military reserve, which has been a training area and artillery range for the Australian Army since World War I. Following World War II it became a major base for the permanent component of the Australian Army in New South Wales. Following the movement of many units of the Regular Army to Darwin in the late 1990s many Army Reserve units were moved from other depots to Holsworthy Barracks, including the Headquarters of the 5th Brigade.

Holsworthy Barracks is the current home to 17 Signals Regiment, 3rd Battalion, Royal Australian Regiment (3RAR), 4th Battalion, Royal Australian Regiment (4RAR), 171st Aviation Squadron and the 1st Health Support Battalion (1HSB).

DFCE
By Jimbo89 - The site no one wants to visit!

This is the aussie equivalent. We call it the Defence Force Correction Establishment (DFCE). It is located at the back of Holsworthy Army Barracks in Sydney's West. The 'gaol' is only the small section to the northern end, the other stuff is minor rubbish like The School of Military Police and some MP Unit. We only keep our bad boys for a maximum for 3 months, worse offences, including escape, go straight to civvy prison. Most guests are at this place for 27 or 28 days. 

Holsworthy Army Barracks
By aussie_abroad

Holsworthy Barracks is home to the Australian army’s most deployable, high-readiness units. It has just been announced that a fleet of Blackhawk helicopters will be redeployed here to assist the Australian Special Forces unit combat terrorism. You can read the media release here.
http://www.minister.defence.gov.au/Hilltpl.cfm?CurrentId=5017

See where Australia's Blackhawks will be stationed

• The Australian Army
• Land Command HQ 1 Bde Home - Robertson Barracks
• Land Command HQ 3 Bde Home - Holsworthy Barracks
• Bradshaw Field Training Area
• Joint Rapid Airfield Construction (JRAC) 2007 Demonstration Project. Bradshaw Field Training Area (BFTA), Northern Territory, Australia. U.S.Army Corps of Engineers - PDF

Holsworthy Barracks Map PDF

I created this out of the list from Wikipedia which contains all of the Army Bases throughout Australia. This included Barracks and few other places only. It doesn't included all of the facility throughout Australia. Just the main ones. It contains all of the barracks that were on that list except for the ones i haven't found yet. See below

Yet to be found
* Derwent Barracks, Glenorchy
* Paterson Barracks, Launceston
* Youngtown Barracks, Launceston
* Kokoda Barracks,Devonport
* Lamina Barracks - Greenhills, Liverpool Military Area, Sydney

As the title suggest, its a work in progress, so i plan to update this. 
Hope you enjoy
Australian Army Barracks - Work in Progress