From 1 June visitors will have to pay R$15 to do the basic tour round the Itaipu dam, near Foz do Iguaçu. Up until now, the visit was free. Notas do Turismo contains the information with a link to a detailed press release by the management of Itaipu detailing the different types of visits to the dam.
In my opinion, the basic tour of Itaipu – the one done by the vast majority of tourists – is of marginal interest. Visitors are shown a video presentation where they learn about the wonderful effect the construction of the dam had on the environment – any mention to the monstrous external debt resulting from the construction of the dam is conspicuous by its absence. After the presentation, there is a quick tour around the external part of the dam.
If the gigantic spillway is closed on the day of the visit (and it only opens when the dam is bursting at the seams) the visit is, to be honest, quite boring. It was free, though. That is not the case any longer, and for any engineering fans, I would recommend the Circuito Turístico Especial visit, where you do enter inside the dam and visit the turbines.
The Buddhist temple near Foz is very near and entrance is free.