If you've ever seen any of the Planet of the Apes movies, you'll know it's a jungle out there in San Francisco. Remember those scenes where Caesar captures the Golden Gate Bridge?
Well, this morning we're on a real urban jungle tour of California's most beautiful city.
We'll venture through a eucalyptus forest. Walk round protected dams that were built to ensure the city was never again without water to quench the fires after a catastrophic earthquake. Stomp up spectacular staircases.
And pause for breath on some of the highest peaks of the city, with 270-degree views of everything from the Golden Gate, Alcatraz and Angel Island to the new city skyline incorporating firms such as Twitter, Google, LinkedIn, Yelp, Uber and Apple.
Max, our guide, gives us a rundown on our eight-kilometre route while we finish our coffees outside the starting point, the Castro theatre.
San Francisco – corsetted by surrounding mountains – is the most densely populated city in the US after New York. So, obviously, there's no green space? No wild flowers? No hidden tracks? No treacherous gullies? No vegetation-clad, former goat paths? And certainly, no World War II precautions in case Japan invaded California?
We see all those things on our walk.
Urban Hiker SF, founded in 2012 by Alexandra Kenin, shows locals and visitors alike a hidden side of San Fran, with three different routes. I've chosen the most popular: Urban Jungles and City Heights.
You'll need to pack a decent pair of walking shoes, water, trail mix, sun screen and a can-do personality.
Our starting point, The Castro (named after what is now a cinema) is one of SF's most fascinating areas, made famous by Harvey Milk – the first openly gay politician to be elected in the US (and the first to be assassinated). It is now home to a sizeable LGBTQI community, and the city's self-described "queer museum" (glbthistory.org/museum) is an additional must-visit.
As Max leads us up from Castro Street, he tells us about Irish-born Jasper O'Farrell, the surveyor who laid out Market Street. O'Farrell apparently wanted the new city's streets to follow geographical contours, but developers won – which is why the city now has more than 670 staircases.
Our first stop is Nobby's Folly, the residence Alfred (Nobby) Clarke built in the 1890s in what was then so much in "the sticks" that the corrupt policeman-turned-corrupt lawyer could never convince his wife and son to leave their more fashionable residence in Nob Hill.
Our first real stop is Kite Hill. But our ultimate destination is Twin Peaks, one of which is topped by Sutro Tower, arguably the city's most detested landmark. When we reach the panoramic viewing spot, with 30 buses disgorging passengers, Max tells us we "are honorary San Franciscans" for walking our way to the view.
From here on, it's mainly downhill. We stroll through a eucalyptus forest, then up again to Tank Hill, possibly the only viewpoint of city's dramatic skyline, harbour and bay, that remains a local secret (and once protected by fast-growing trees to prevent Japanese planes bombing it after Pearl Harbour).
We see blackberries, an avocado tree, and learn about the city's Mexican history when the Twin Peaks were called Los Pechos de da Chola ("breasts of the Indian maiden," apparently) when this whole part of San Francisco was just made up of several ranchos.
Our last stop is Pink Triangle Park where 20 obelisks commemorate the thousands of LGBTQI people forced to wear a pink triangle by the Nazis in Hitler's Germany between 1933 and 1945, the majority ending up in extermination camps.
Yes, it's a walk on the wild side – and one of constant surprises.
Urban Hiker SF offers three walking tours that take you off the beaten track. Urban Jungles and City Heights (US$49) begins at The Castro and includes everything but entrance to the LGBTQI museum. See urbanhikersf.com/
Fiji Airways flies from Sydney, Melbourne and Brisbane to San Francisco, via Nadi. See fijiairways.com
Steve Meacham travelled courtesy of Fiji Airways and San Francisco Travel.