Coober Pedy is a town made almost entirely of corrugated iron - every above-ground building incorporates some of it. Walls, window sills, roofs and fences are made from corrugated iron. Even some toombstones are made from corrugated iron. There's hardly any green vegetation in town or anywhere in the surrounding landscape which is perforated by abandoned opal mines. Signs lining the road warn travelers to not depart from the beaten track, lest they wish to spend the remainder of their days starving to death with a broken leg at the bottom of a 30-meter mineshaft. Freezing nights are interleaved with scorching days, and the dry wind blows fine dust into every crevice of your sweat-covered body. The streets (of which only a few are sealed) are lined with derelict, rusting mining equipment, stray dogs and drunks. The buildings that are not abandoned feature signs hawking goods or services somehow connected to opals; sell, buy, essay, visit the mines, whatever.

I love the place.

Where people live underground and opals are dug up. (Some facts to add to spazzm's writeup above.)

Coober Pedy is in approximately the center of South Australia, and is a mere 846 km of lonely driving north-west from Adelaide via the Stuart Highway. The name comes from the Aboriginal word kupa-piti which means "boys' waterhole," which as far as I can tell comes from the language of the aboriginal group Anangu, who populate(d) northern South Australia. The Anangu group can be separated into various other groups. I am not sure which particular group or "tribe" of aboriginals the word kupa-piti comes from.

The weather in Coober Pedy is typical desert weather. While in winter it is bearable, ranging from around 10 C to 20 C during the day, the nights are very cold. So cold, in fact, that one is not allowed to disembark the train at the isolated Manguri Siding 42 km away unless you have prior transport. During the summer months, November to March, it is hot. In the shade it can reach up to 45 C, with an average high around 35 C. For this reason, people live in caves dug underground. Underground the temperature averages a decently warm 25 C year round, and so people don't need air conditioning down there. A rainfall of 5 inches a year is average and can happen at any time. Coober Pedy is in the desert. None of this should be especially surprising.

The landscape is as bland and raw and Australian as it should be: red dirt, burning blue sky with the occasional hill (discounting the rabbit hole houses and dirt mounds from the mining) and the even more occasional tree. Grass is a rarity, as it is in most of the Australian outback, so livestock cannot be grazed in or around Coober Pedy. And so the town and surrounding area is good for only one thing: mining.

If you have an opal, chances are it comes from Coober Pedy. It isn't called the opal capital of the world for nothing. Opals were first found on February 1, 1915, and since then it has turned into the world's largest supplier of the stone.

Various films have been set in and around Coober Pedy, including Pitch Black, The Adventures of Priscilla, Queen of the Desert and Mad Max Beyond Thunderdome. It is a common stop over point for people traveling to Alice Springs from Adelaide, who are mostly tourists. It's a place I doubt you would see: most tourists use a plane to get directly to the Red Centre.

Sources: http://en.wikipedia.org/wiki/Coober_Pedy,_South_Australia and knowledge I picked up over the years.