The world has a surface area of just over 510 million square kilometers, and a population (as of 2008) of about 6.7 billion. This leads to an average global population density of about 13 per square kilometer, but in practice, people are highly concentrated in cities and around arable land, making the average population density for many areas much less. Some gigantic regions, such as the Sahara Desert, Siberia, and Greenland only harbor a few thousand people every hundred thousand square miles. Some of the world's most isolated places are very cold or very dry, but not necessarily.

For starters, the most isolated place in the entire world is likely Antarctica. 14 million square kilometers, inhabited by about 4,000 research scientists in the summer, 1,000 in the winter. There are just over 25 research stations in the Antarctic, all but a few located within a hundred miles of the coast. Aside from the Amundsen-Scott research station at the South Pole, the Antarctic interior is essentially empty. This makes sense -- here at the ends of the Earth, rain barely ever falls, the Sun doesn't shine for weeks or months on end, and temperatures drop as low as −90 °C (−130 °F). Not a place to plan your vacation.

Another of the world's most isolated places is Tristan da Cunha, the most remote archipelago on Earth, 2816 km (1750 miles) west of South Africa. Tristan da Cunha is located in the south Atlantic, about halfway between southern Brazil and South Africa. With a population of just over 250 people, Tristan da Cunha's economy is based on its lobster factory and the sales of stamps and coins to collectors overseas. The closest major city, Cape Town, is a three-hour flight away. Due to its geography, the South Atlantic has very few islands.

When it comes to the most isolated places on the main inhabited continents, some of the top contenders are Koryak Okrug, in far east Siberia, with a population density of only 0.1 people per square kilometer, certain parts of Northern Siberia, the West Australian Desert, and Northwest Canada. In some of these areas, it would be possible to detonate an atomic bomb in plain sight, and not a single person would notice. In some of the most isolated areas, the population density fails to convey the true loneliness of the area, as most of the population is clustered in towns and villages separated by hundreds of miles.