Coober Pedy, Australia
This mining town in Australia's Outback is considered the opal capital of the world. The first stop for those interested in subterranean wonders is a tour of an opal mine, but mines are only one type of underground attraction in Coober Pedy. The harsh desert weather makes living underground the best option for people who work in the mining industry. In addition to homes, there are subterranean churches (shown here), restaurants, bars and hotels all around Coober Pedy. Visitors can stay in a hostel that was once used by miners who would dig for opals right outside their rooms. You won't find thousands of years of human history in this Australian town, but you will find a thriving community of people for whom living below the surface is a way of life.