The driest desert in the world, Atacama is where most Mars situated movies and TV shows have been filmed. It covers roughly 1,000 km (600 mi) land strip, consisting of parts of southern Peru and the west coast of Chile. Rare precipitation due to a double-sided rain shadow is responsible for its unique dryness; NASA has been unable to detect any signs of life on a couple of regions in the desert, duplicating its tests performed on Viking 1 & 2 Mars landers. This makes the Atacama desert a remarkable place to visit.
A range of activities are available in the desert of Atacama. I will speak here of San Pedro, a city in Chile that lies close to the Bolivian border. The town of San Pedro is very vibrant, with lots of dining and nightlife options. Also, the city holds an array of different accommodation options, from budget hostels to expensive hotels. Different desert valleys can be accessed by either bike trekking or cabs. Most of the interesting valleys are not too far from the city, which makes bike trekking a better option, in my opinion.
Contemplating delightful lagoons (Miscanti & Miñiques), hiking on moon-like structures (Moon Valley), sand-boarding on Mars-like sand dunes (Death Valley), relaxing in hot springs (Puritama Springs) or star watching/gazing, San Pedro de Atacama has it all. The latter needs to be done with a tour agency, unless you plan to take your telescopes with you to San Pedro. All the rest can be done on your own.
The closest commercial airport to San Pedro is in Calama, which is about an hour away. Convenient shuttle services between the two are available. Flights to Calama can be taken from any large airport in the region; it is a relatively popular destination.
On another note, I wrote about how to get to San Pedro from Uyuni, Bolivia on my blog post for Bolivia, so refer to it for more information. Anyway, here are the options:
1- Bus: 20+ hours, involves changing buses at the border of Bolivia-Chile.
2- Private 4×4 car, straight 8 hour shot. Car costs $500-$600.
3- Taking a 3 day/2 night tour. First night you spend in Uyuni after touring the Salt Flats. Second night you spend around Laguna Colorada, a national park with decent scenery and home to lots of flamencos. Costs about $100/person including food, accommodation and ticket to Laguna Colorada national park (worth $20).
4- Taking a 4×4 car that is doing the opposite journey (going to pick up people from San Pedro). Costs about $70/person, including food, accommodation and ticket to pass through Laguna Colorada national park. Trip takes two days, spending one night in a small village called Vila Mar. This option is transportation only, no tour included.