This is the normal first stop at panoramic tour to the Itaipu Dam , the largest generator in the world!
If you luck the spillway open, but it is only open 5% of the days in the year.
You can go to visit it by bus to the entrance , but i do recomend to hire an local expert to optimize your time here!
more info: https://iguassubyfrancis.com/itaipu-dam-one-wonder-of-the-engineering/
This is one of the wonders of engeneering!