So you use your wealth to ensure that local authorities protect your interests. You setup people in power, vassal kings, to protect land interests above all others. Who is in charge now? Who are their friends? Do they own property scattered all over the globe? Do any of them care about a box of gold?
I wouldn't agree with what you say completely. I wouldn't say gold is replaced by real estate. That doesn't mean that real estate can't be a source of power, though.
I'd recommend you reading this interview with M. Burry (guy who foresaw the real-estate crises in '08): http://nymag.com/daily/intelligencer/2015/12/big-short-geniu...
If one wants to get all conspiracy-minded: Vancouver, Toronto ... not the warmest of cities. Neither are they in red zones for rising sea levels. And, being in Canada, have more fresh water per person than most anywhere on the planet.