Chimney

Could be old mining flues, or maybe remnants of a ruin . . . quite often only the stone chimney remains as they were usually of fairly strong construction.

If there has been a gold roaster in the area, there will often be a substantial chimney stack remaining.
Roasters are used to extract many other valuable minerals, as well as gold.

Gold is found in "oxidised" ores and in "sulphide" ores. Oxidised ores extend from the surface to the shallower depths, often no more than 50-100 metres deep.

Once you have reached the limit of the oxidised ore, you are into sulphide ore - usually defined by appearance as very hard rock or very dark blue rocks.
Oxidised ores are called "free-milling" ores. The gold is easily won by simple crushing or grinding, or both.

The gold in sulphide ores is not easily released by crushing or grinding, because it is chemically bound in with the associated sulphide-based minerals (mineral elements chemically combined with sulphur).

As a result, sulphide ores need to be roasted at high temperature to break down the sulphide elements, so the gold is released for extraction by further crushing and grinding and cyanidation.

Roasting releases free sulphur, which turns into sulphur dioxide gas when it comes into contact with air - and a tall chimney was always deemed necessary to carry away the highly noxious and poisonous sulphur dioxide gas, which is released by roasting.

There's a fine example of an old gold roaster chimney at the Comet Mine, just out of Marble Bar. The Comet chimney is unusual, as it is steel.
It was built out of steel because the cost of transporting bricks to Marble Bar would have been astronomical.

The biggest chimney stack in the W.A. Goldfields is the stack at the Kambalda Nickel Smelter, 20kms South of Kalgoorlie. This is also a steel chimney stack.

The oldest chimney stack in W.A. is the The Warribanno Chimney at the old Geraldine Lead Mine, East of Kalbarri.

This chimney was originally 105 feet high (32M) and it was built in 1854.

The lead ore here had to be roasted to release the lead in metal form.

https://www.flickr.com/photos/railwa/8059489874

https://en.wikipedia.org/wiki/Roasting_(metallurgy)

Old brickworks also had chimney stacks to assist in firing bricks.
The abandoned Clackline Refractory, just East of Bakers Hill, still has an excellent industrial chimney standing.

The Clackline Refractory produced house bricks, fire bricks (one of their specialties), and gold-sampling fire-assay crucibles for over 80 years.

https://somewhere42.wordpress.com/2015/03/01/industrial-past-5/

Thanks heaps Ron, I will know to be on the look out for now, the closest thing I saw was an inground concrete tank so might be on the right path, just need to keep a better eye out. Thanks again everyone