Iguazu Falls are a natural wonder and Itaipu Dam, nearby, an engineering wonder.
Itaipu Dam (Portuguese: A Usina Hidrelétrica de Itaipu Binacional, Spanish: La Represa Hidroeléctrica de Itaipú) is an enormous structure of concrete, iron and steel.
It is the longest hydroelectric power plant in the world, generating 25% and 90% of electric energy consumed by Brazil and Paraguay, respectively; and the second largest in total generating capacity only after the Three Gorges Dam, China.
After the dam was constructed on the Paraná River, the border between Paraguay and Brazil, and was filled with water, many spectacular waterfalls were submerged. Iguazu Falls are just downstream from the dam.
For a visit, you can take a local bus to the dam in Foz do Iguaçu, Brazil. Itaipu Binacional company, which operates the dam, runs daily tours. It is not a very interesting tour, just being driven around in a bus near the dam for a short time, but it is free.
Itaipu Binacional – www.itaipu.gov.br