which is nice because it is cold there at night. Then very early the fourth day we went to the Salt Flats and watched the sun rise. It's really awesome because it is the biggest salt field in the world. It's like an inland sea but one that is flat  and white. It is quite amazing and rather eerie. We drove right on top of the flats. There's an island there with lots of cactus. We had fun taking photos because all that whiteness fools the eye. This four-day circuit was a highlight of my South American trip. We actually knew very little about it and thought it would be just a side trip.  But it surprised us because it was so unique. It was also super cheap -- something like $120 for four days. It was quite different from our trek to Machu Picchu for that required making arrangements from home and it cost a lot of money. There are big changes when you travel from country to country in South America. Bolivia is very poor. For instance, when we went to a restaurant in Bolivia there wouldn't be any locals eating there because they couldn't afford it. But when we crossed the border into Argentina, we couldn't afford to eat in the same restaurants as the locals!