Distances are so vast in the world's most isolated capital city, that the term, "near Perth" was actually, "one heck of a long journey" to the arriving prospectors.  Sure, there may have been a bit of empty real estate to cross from Perth to the Goldfields (600km), but this all fell in Perth's favour.  Most of the prospectors turned up in Perth first, before finding out about that nasty distance thing.
 

PERTH ALERT:  Western Australia is one mighty big place.  Over 2.5 million square kilometres to be exact.  We can swallow up whole countries, within our borders.  Don't be caught out like the gold prospectors: Bring a second pair of shoes.

With spaces left over for small Pacific Island Nations.

With an expanding population, and all that new wealth available, Perth experienced one major super sized upgrade.  Hotels, banks, shops and everything else the economic boom could offer turned up on Perth's doorstep.  This included the Trans-Australian Railway which arrived in 1917.

Perth showing the first signs of an upgrade.

Both the World Wars slowed down growth and development in Perth.  The local workforce suffered as Perth residents left to join the fight.  During World War Two, defensive guns were positioned on Buckland Hill, as the fear of an invasion increased.  Nobody actually invaded Perth. Though it was later decided that a peaceful invasion on our shores, might just be the answer to kick things along.

Now used as a deterrent for tourists without valid Surfing Licences.

To boost the population and workforce, Perth resorted to special migration schemes.  Initially most of the migrants came from the United Kingdom.  Eventually the rest of the world came down.  Today Perth is a multicultural society, with a rich ethnic diversity permeating it's population.