The elegant capital of Argentina on the River Plate, which once styled itself the Paris of South America, a city of grand boulevards, cafes, and squares made for walking. Read the founding square of the Plaza de Mayo and the avenue that runs from it to the domed Congress, wander the marble avenues of the Recoleta Cemetery, and feel out the cobbled birthplace of tango in San Telmo. Best taken slowly, at your own pace.