In the 19th century, the main colony of Perth was built about 20km up the Swan River on a low-lying land of lakes and swamps due to – according to a local historian the Herald encountered here shortly after arrival for Saturday's Bledisloe Cup test – ease of defence.
Any invading ships that made it over the protective sandbar would presumably be vulnerable to attacks on either side of the river.
Cities don't come much flatter than this one perched on the edge of the Indian Ocean, so it was about making the best of what you've got and preparing accordingly.
Which brings us in a very roundabout way to the test between the Wallabies and All Blacks at the magnificent new Optus Stadium built within a clearing kick of the Swan across from the cluster of skyscrapers which mark the central business district of this now prosperous and pleasant place.
That's because the talk of this All Blacks team being "vulnerable" as suggested by former Wallaby Phil Waugh may have handed All Blacks coach Steve Hansen all the metaphorical ammunition and high ground that he needs in order to find the performance he and his team are craving.
If there was an edge missing from the All Blacks in Buenos Aires and Wellington recently, there is no excuse for it to be absent in a sold-out stadium filled with gold replica jerseys on Saturday.
There are many New Zealanders here but the locals will ensure the All Blacks know they're in enemy territory and that, combined with what is at stake – a cherished trophy played for over the next two tests - should combine to bring out the best in the visitors.
Talk of vulnerabilities will be music to Hansen's ears and could lead to smoke coming out of rival coach Michael Cheika's because nothing provides motivation like criticism, implied or otherwise, from an opposition camp.
"They're not nearly as dominant as they were - almost to the point where you could say are they the best team in the world at the moment? I really don't know," former loose forward Waugh said recently on Australian television.
Shot fired and narrative established, it was down to the Wallabies to attempt to douse the flames, starting with outside back Reece Hodge. A prediction: Neither Hansen nor Cheika will say anything which could be construed as remotely inflammatory when they face the media separately on Thursday.
"I definitely wouldn't say they're vulnerable," Hodge said. "We are confident in ourselves and what we're trying to do but they're going to be extremely confident themselves as well.
"They would have been trialling a few things ahead of the World Cup. I'm sure they're confident that's going to come to fruition on Saturday.
"I don't think they'll be talking about any vulnerability in the camp. It's up to us to really go out there on Saturday and test them as much as we can."
The All Blacks and Wallabies have a long and rich playing history which has featured classic tests, huge disappointments for both sides, flare-ups, fist-fights and last-minute winners. The All Blacks won all three tests last year in Sydney, Auckland and Yokohama fairly convincingly, but the year before they needed a last minute try from Beauden Barrett to win an extraordinary test in Dunedin.
The bottom line is the Wallabies last held the Bledisloe Cup in 2002 but have always had the ability to cause the All Blacks difficulties due to their inherent confidence no matter the situation. It is a special rivalry.
"They're the team that has been really been able to get under our skin the most, probably," assistant coach Ian Foster said. "They know us well, they'd love to beat us and we know it's a battle royale."
Cheika and company may indeed sense the All Blacks are vulnerable, but they would be wise to keep it to themselves this week and next.