STUART HIGHWAY LONG, FLAT, FLAT AND LONG.930KM of the 2722km Stuart Highway is in South Australia. Besides the much over-rated Coober Pedy, there is, well, there is a lot of open space. South Australia has some long, sparsely populated roads, heading west to Perth and north to Darwin. Triple-trailer road trains must be treated with respect and caution.On the other end of the scale, the Solar Car Challenge, from Darwin to Adelaide, sees futuristic, lightweight cars race powered only be the sun.Road houses pop up every few hundred kilometres, so get your maths right when working out fuel stops. Those shoes are from drivers who perished after running out of fuel. Nah, just kidding.Big, open, blue skies are a feature of South Australia's outback. Night skies glitter with stars.Port Augusta is 300km north of Adelaide, and the junction for roads west and north, as well as to Ikara-Flinders Ranges.The town's Arid Lands Botanic Garden showcases many of the plants which thrive in these harsh environments. if that hasn't won you over, their cheesecake really rocks.Another wattle species at the Botanic Gardens.The flora emblem of South Australia, the Sturts' Desert Pea. Strange looking fellow.At a look-out near Lake Hart Dreaming here refers of course the the local creation stories, but you can see the white man's dreaming too.Driving through the centre of Australia needs (or develops) an appreciation of vast and flat open spaces.Lake Hart is a dry, salt bed, about half way between Port Augusta and Coober Pedy. Approaching, we fell for the illusion of water.The pancake flat bed of Lake Hart stretches to the horizon, shimmering white.A small and basic campground there makes a great overnight rest spot, with orange sunsets meeting the salt bed.Every few years, Australia's inland lakes fill from either flows from the tropical north, or from the rare local inundations. Bird life flocks to the water.There had been heavy rain in Queensland that year, and Lake Eyre had put on a spectacular show of nature when it filled. We "saw" the blue waters as we approached Lake Hart and couldn't believe our luck! Of course, there was no water there, but it is breathtaking nonetheless.Coober Pedy, opal capital of the world is bloody hot, so people live underground. People from all over the world have come to seek their fortune. The Serbian Orthodox Church of Saint Elijah, built in1993, is not the only underground church in town.The Old Timers' Museum takes you deep down into an old mine, and shows the workings as well as living conditions in a miners house.Possibly Lake Eyre, which fills roughly four times a century, although it gets small floods every three or so years, and larger ones every ten.Water, specifically, a lack of it, has always been a defining feature of Australia. Early white explorers searched in vain for a great inland sea. Indigenous people have tens of thousands of years of knowlegde of water sources in the arid outback. Their knowledge was often the difference between life and death for explorers.