The designation of famous cities is primarily based on cityquiz.io and quizzes about cities in South American countries. The population and rarity scores listed on cityquiz.io are provided for reference. Please note that the renown of a city may not only be attributed to its population and economy but also to historical events, historic architecture, tourism, etc.
Really surprised by a some of these- Rurrenabaque (BO), El Chalten/El Calafate (AR) and Cafayate (AR) are pretty famous towns, especially among tourists
You are right, this quiz doesn't sufficiently cover smaller tourist cities. Users of cityquiz.io and JetPunk generally prefer larger cities with higher populations. Currently, I am incorporating other data sources, such as Wikipedia page views, into the existing data. I will reset this quiz series in the near future.