Tupiza is a small city, with nothing much to do. But its located in a fantastic mountain area. Its the best place in South America to feel like you’re in a Western movie. The landscape feels like the Old West, and if that isn’t enough to get your fantasy going: this was the area where Butch Cassidy and the Sundance Kid found their end.
If you like horses, this is the town where everything is possible. Ask for a slow horse or a fiery stallion. The canyon floors are perfect for galoping until your ass comes off. The most efficient way to do this is on a two day trip, but other options abound. There are also tours that combine horsebackriding with biking (cross country and a 800 meter decent).
It’s actualy better to visit the Salar de Uyuni from Tupiza than from Uyuni. Agencies are generaly better and you skip the boring ride back to Uyuni. It’s bound to be a surreal experience and one that is cheap: four days, all included, will normally not surpass 100 dollars.
If you want to do something in town, you can always circle around the plaza again and again, like the locals do for entertainment. There are plenty of reasonable restaurants, especially Italian styled ones.