Slide showing a photograph of a Silver mine. Broken Hill is Australia's longest-lived mining city. In 1844, the explorer Charles Sturt saw and named the Barrier Range, and at the time referred to a 'Broken Hill' in his diary. Silver ore was later discovered on this broken hill in 1883 by a boundary rider named Charles Rasp.. Boswell Collection. Slide number 55. Sydney is the most populous city in Australia and the state capital of New South Wales. It is located on Australia's south-east coast of the Tasman Sea.