Argentina has a wonderful bus system which is ran by many different companies. Overnight sleeper buses go to and from Buenos Aires to all parts of the country. These buses have sleeper seats that open flat and are as comfortable as first-class on an airplane. Meals and snacks are served in route. The following tours to various parts of Argentina utilize these overnight buses.
This 13 day tour to Patagonia National Parks and glaciers in southern Argentina and Chile leaves from El Calafate. El Calafate can be accessed by air or bus from Buenos Aires.
See one of the best waterfalls in the world, shown above. The following tour leaves from Buenos Aires.