The Operations and Signals building of 3 Fighter Sector Headquarters was constructed between 1942 and 1944. In January 1945 the site became the RAAF Air Defence Headquarters. The timber camp buildings (not extant) north of the two storey reinforced concrete Operations building were later used for migrant accommodation and as student accommodation.

The Operations building, measuring about 18m by 13m, is located at the base of Mount Stuart, and is approached from the northeast by a track from Stuart Drive (Flinders Highway) at Wulguru, south of Townsville.

The main interior space is two-stories in height, with internal support pillars, and retains evidence of the destroyed mezzanine floor, air-conditioning ducts and toilets. The skillion-roofline section to the north contains a single storey (roofless) guard room on the east side, a former stairwell and four rooms on two levels. Access to the (roofless) upper and lower rooms (air-conditioning room and engine room respectively) at the centre of the front elevation was from the stairwell; access to the upper and lower rooms at the western end was from the interior.

To either side of the Operations building are two circular structures, possibly bases for communication aerials or anchors for the camouflage net for the building. To the northwest and the northeast of the Operations building are a number of concrete slabs, concrete steps and scatters of building material; remnants of the other structures of the headquarters camp.