Walk along the Circuito superior
The upper circuit is one of the easiest of paths to trek. The total walking distance is less than a mile and you have easy vantage points to see beuatiful sights like this.
Getting up close
The Argentine side of the falls has a lot of different trails that take you to different parts of the falls. You can really get up close to them on the Argentine side.
Boat Ride Into the Falls
If you visit the park you must take the Boat Ride where you ride up into the edge of the Falls enjoy a spectacular view and get soaking wet.
The devils throat
This is one of the most impressive parts of the falls, The devils throat or Garganta del diablo (in espanol) is a location where a lot of the river meets and the results are spectacular.