The Itaipú dam operator also provides a number of tourist attractions and tours, including the Tati Yupi Biological Reserve, some of which require registration. And you will mostly always need some form of identification, so bring your passport. And for registrations require ahead of the tour, they will need names, ages and number of people.The most convenient option is the simple Panoramic tour of the dam. However, it is worth booking a scheduled tour ahead, for a more interesting and different experience. You can still always do the regular tour.