The salt flats of southwestern Bolivia will have you feeling as if you're on another planet. First you will see old abandoned trains from the 1940's as you enter the desert landscape. Then the scenery becomes whiter and dryer as the salt flats surround you, punctuated by coral islands from when the flats were an actual lake. Eventually the salt gives way to desert and you will see various colored lagoons populated by pink flamingos.
Most people take a 4-wheel-drive tour from Uyuni but other starting points are also optional. Alternatively, you can rent a dirt bike or ATV or take your own 4WD to do this tour on your own. Various hotels exist along the way, some made of the very salt they sit on.