There is no doubt that the main attraction in Iguazu (or Iguassu) are The Falls.
The traditional visit to Iguazu includes a tour to the National Park Iguazu in the Argentine Side (full day activity) and on the following day, a half day tour to the National Park Foz do Iguacu from the Brazilian Side. Then, you need at least one night to spend in Iguazu, just to see the Falls from both sides.
However, Iguazu has a lot more to offer. Let’s try to make some suggested itineraries depending on the amount of days you can spend around.
All right, you are really tight, so there is no time to waste in order to see the Falls from every angle.
On the 1st Day you should be arriving early in the morning to Iguazu Airport (Brazilian or Argentine Side). Then you can take the excursion to the Argentine Side of the Falls (Parque Nacional Iguazu). It takes around 20 minutes to get there from Puerto Iguazu, and then you would spend the whole day walking the footbridges over the water.
Do not forget to add Gran Aventura, an amazing boat ride under the falls.
On the 2nd Day the best option is to visit the Brazilian Side of The Falls (Foz do Iguacu National Park).
You can enjoy a panoramic view of the Falls, a great option to take the best pictures of your trip.
This would take you just half day, so right after the excursion you should be ready to be transferred to the airport. Book flights after 2-3PM!
2-Nights Trips (Recommended)
Puerto Iguazu (the closest town to the Falls from the Argentine Side) has really good hotel accommodation. It is one of the most important touristic places in Argentina. With two nights to spend in Iguazu we suggest to enjoy a good hotel.
On the 1st day you can arrive anytime. Get to your hotel and enjoy the swimming pool, the restaurants, take a walk to the town and spend some time in the local crafts fair.
On the 2nd day, take the excursion to the Argentine Side of The Falls. Spend the whole day in the Park, walking around and staring at this unique landscape. Again, do not miss the Nautical Adventure, the boat ride to get the closest possible to the Falls.
On the 3rd day, You can visit the Brazilian Side of The Falls (Parque Nacional Foz do Iguacu). That would take you half day. If your flight is at 3pm or even later, do not miss the helicopter ride over the Falls before going to the airport. It is just a 12-minute ride, but will be one of the best experiences of your life!
Ok, now you have one more day to enjoy the surroundings.
Take a tour to the San Ignacio Ruins, ancient Jesuit ruins. This is the option if you like history.
If you want to keep with the Nature theme, there is one great activity in the jungle: Iguazu Forest.
This excursion includes canopying, hiking and rappel around Iguazu Falls.
If you are staying on the Brazilian Side, you can also visit Parque Das Aves, a non-traditional Zoo where you see the animals and birds in their own environment.
Assuming that you might take an overnight flight to go to South America, and that you will be visiting unique places in the World and who knows when you will be able to get back if there is any chance; the perfect amount of time to spend in Iguazu is 3 nights.
But if you ask me how long should I spend in Iguazu Falls or how many days in Iguazu at least? Then the answer will be 2 nights in my opinion.