The drive into the salt lakes is like stepping into a surreal world. The lakes are so large that very soon there is no reference point and all that one can see is the whiteness of the salt as far as one can see. Landmasses appear as mountains, and are referred to as islands by the locals. Some of the salt lakes have some water and this is populated by flamingos and other water birds.
On the last day heading off to the Chilean border, one passes through the highest point and the geothermal areas. Imagine seeing steam and geysers while playing in the snow!
Quick Tips:
The trip to the Salt Lakes can be made commencing from Chile and finishing in Uyuni. However, be aware that the lakes are above 4,100 metres and settling at this altitude from lower levels takes some time. Even though I was in the antiplano traveling progressively from 2,300 metres to 4,100 metres over a period of 3 weeks, I still suffered from altitude sickness (thankfully only on the last night).
Best Way To Get Around:
The best way to explore the region is with on a 4WD tour. There are a number of tour groups operating from Uyuni, traveling through the salt lakes and ending near the Chilean border. From there, you can head off into Chile or spend a full day's drive back to Uyuni. The best overall tour group is Colque. They run a number of vehicles and have a somewhat professional approach. Their guides can be sullen and unhelpful. I used Pukara Tours and would not recommend them. This tour company engaged a free-lance guide to take us around and he certainly cut corners with respect to accommodation and side-trips. The costs are the same for every tour group (is there a racket?) at US including food and accommodation.