Marquis, now 43, was born in a small village in northern Switzerland's Jura Mountains.

She says she grew up curious and spent most of her childhood running wild in the Swiss countryside, climbing trees and watching birds.

When she was eight she ran off with her dog and spent the night in a cave.

"You don't become an adventurer, you are one," she says.

As she grew older her adventures became grander and more far-flung.

Over the years she's hiked New Zealand, crossed the United States, walked 14,000 kilometers across the Australian outback and trekked the Andes.

But in 2010 she set out on the ultimate odyssey.

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Her three-year journey took her from Siberia, through the Gobi Desert, China, Laos and Thailand.

She then boarded a cargo boat bound for Brisbane and walked across the entire Australian continent, ending her three-year journey under a tree in the desert, a tree she first found a decade before.

Struggle to find food

Marquis first turned her hand to hunting at the age of seven, when she was tasked with weeding slugs out of the family vegetable patch.

Living off the land has been a recurring theme in her adventures, but one of the biggest takeaways from this experience was discovering how hard it was.

"I wanted to go back to human origins -- Aborigines lived like this 60,000 years ago," says Marquis. "But I realized the difficulties and hardships there were in finding enough food.

"It made me think about the challenges we face in finding enough food for the whole planet."

Finding food was just one of the many obstacles Marquis had to overcome on her journey.

She also had to keep her mind active and her body safe, both of which presented their own challenges.

"I had to keep my ultimate goal in mind," she says.

"But at the same time just think about one step at a time -- and try and stay in the present. I always had to stay alert and focused."

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This was particularly important during several threatening situations.

"I was camping in the Gobi Desert, and at 5 a.m. one morning five wolves came howling around my tent," she says.

Rather than be terrified, Marquis says it gave her a "sense of belonging to the planet."

"Nature can go on without us being human," she adds.

'Sometimes I wish I had a man's muscles'

Sadly, but maybe not surprisingly, the event that scared her the most relates to humans.

She says was attacked by gun-wielding drug lords in the Laos jungle in the middle of the night, an event that she says shook her.

"I am proud to be a woman," she says, "but sometimes I wish I had a man's muscles and hair everywhere."

She doesn't leverage her femininity in discussions around her accomplishments, but equally doesn't deny she's faced additional challenges due to her gender.

"I had to disguise myself as a man in certain countries that lack rights for women," says Marquis.

"In parts of China, for example, any woman alone is considered a prostitute."

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"There are not that many adventurous women, and I'm proud to be a free woman who can act as a reminder for all the women throughout the world who are still fighting for that freedom."

Marquis is an established speaker and has just published a book about her experiences over the three years.

Even so, she insists she's just "the girl next door" and is firm in her belief that anyone can have an adventure if they set their mind to it.

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It might not be a 1,000-day walk, but "we all have an adventure hidden inside of us," she says.

"In the middle of the Gobi Desert -- it's inner strength that's important, and there, we are all the same."