You can visit one of the five underground churches in town, as well as dugout cafes, bookshops, galleries, and plenty of underground opal showrooms. Most are located along the main street, or you can find details at the visitor's information center.
Worth seeing is Umoona Opal Mine and Museum, on Lot 14, Hutchison Street, one of a couple of opal-mines-cum-museums in town. There are four tours daily at 10am, noon, and 2 and 4pm (A$10 for adults and A$5 for kids). There's an Aboriginal interpretive center, a gallery, an old opal mine, and of course the ubiquitous opal showroom and shop. Entry to the museum is free.
About 30km (18 miles) from town are the Breakaways, a series of flat-topped hills or "jump-ups." Head out here at sunset, when it's not only cooler but the sandstone pillars, pinnacles, and gully edges glow pink, red, brown, purple, yellow, and white in the fading light. Just a bit farther down the road, you'll find the famous dog fence and the Moon Plains -- the nickname for the moonlike desert landscape along the fence. The 2m-high (6 1/3-ft.) dog fence stretches across three states for more than 5,300km (3,293 miles) in an effort to keep northern dingoes away from southern sheep; it's the longest fence in the world.
If you want to see parts of Australia that most Australians never see, join an honest-to-goodness Mail Run (tel. 1800/069 911 in Australia), with a postal carrier, for a 12-hour journey out into the bush. Tours leave Monday and Thursday from Coober Pedy's Underground Books (tel. 08/8672 5558) and travel along 600km (372 miles) of dirt roads to Oodnadatta and the William Creek cattle station, stopping at five stations along the route. Tours cost around A$190 for adults. This up-close-and-personal look at life in the bush could easily be one of the most memorable experiences you'll have in Australia.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.