The Itaipu Dam is an engineering feat on a scale that is hard to grasp until you are standing in front of it. Completed in 1984 after 16 years of construction involving 40,000 workers, it spans 7.9 kilometres across the Paraná River and stands 196 metres tall. The reservoir behind it stretches 1,350 square kilometres into the interior of Brazil. To build it, the Brazilians and Paraguayans had to divert an entire section of the Paraná River — an operation that reportedly used more earth than the Panama Canal.
Guided tours run from both the Brazilian and Paraguayan sides. The Brazilian tours take you inside the dam structure itself, down into the turbine rooms where the generators whir in a vast cathedral of concrete. The night panorama tour, which runs on selected evenings, is especially dramatic — the dam is lit up across its full length and you can see both the Brazilian and Paraguayan sides simultaneously. The Ecomuseu de Itaipu, a few kilometres away, covers the social and environmental history of the project, including the displacement of communities and the flooding of the Sete Quedas waterfalls — once the largest in the world by water volume and now permanently submerged.