Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Buenos Aires (78% of total searches to Northern Argentina). The next most popular destinations are Puerto Iguazú (13%) and Río Ceballos (6%). Searches for hotels in Mendoza (4%) are also popular.
KAYAK users have found double rooms in Northern Argentina for as cheap as $11 (Puerto Iguazú) in the last 3 days. The average price is $142.