Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Cartagena (30% of total searches to South America). The next most popular destinations are Medellín (27%) and Buenos Aires (23%). Searches for hotels in Bogotá (21%) are also popular.
Based on KAYAK hotel searches, the most popular region to stay in South America is Bolívar. Antioquia and Capital Federal District are also very popular.
KAYAK users have found double rooms in South America for as cheap as $6 (Sao Paulo) in the last 3 days. The average price is $103.