How to visit both sides of Iguazu Falls in a day?

How many days one need to visit Iguassu Falls?
We recommend people to split it in two days, but we know that some people need to do it in one day to catch up with the travel schedule.

​Yes, it is possible to do it in a day. To do both sides of the falls in one day, one must be a good walker. There are trails to cover on both sides. Depending on the hotel people stay at and the time of the year, one can start with the Brazilian side and finish with the Argentinean side or vice-versa. 

In case one decides to visit both sides of the falls on private transportation in a day. There is also time for the boat ride under the waterfalls but one needs to skip one of the trails in Argentina. Please, bring shampoo. 

We are reminded that there are borders to cross and a Passport is mandatory. During high season and holidays one can face lines at Iguassu borders.