Savage Australia

It's been 65 million years since a massive asteroid smashed the earth and whipped out every dinosaur and marine reptile - expect one. The earth's largest living reptile and some say the animal most likely to eat a human, is the salt water crocodile. They're incredibly aggressive and territorial, they inhabit the northern parts of Australia and can measure up to 7 metres long.

Australia is a mecca for tourists, each year thousands flock to the beaches, the mountains and the outback for an up close and personal brush with nature. Most return to their homeland with a suitcase packed with happy memories. With unforgettable experiences, but beware - reach into a rock pool or wander down a lonely bush track and very quickly things can go very bad.

Australia's native plants and animals have adapted to life on an isolated continent over millions of years. Evolving over eons into unique and amazingly varied species. Then came Europeans, but it's not just the people that changed the land forever. It's also what came with them. Over the next hour you'll witness the devastation of the lands and the waterways.

Since European settlement over 200 years ago, Australian towns have been built on flood plains despite dire warnings from local Aborigines. Into the distant past, flooding on an epic scale has been a regular seasonal phenomenon across the eastern half of the continent. A powerful part of the natural cycle, but these life-giving waters can also carry death and destruction.

Australia is no stranger to wildfire. It has stalked the land down through time, a primal force. But man has increasingly populated areas in fire paths and is only now learning we are no match for the ferocity for an Australian fire storm. In this episode events that defined a nation. Stories of survival.