Paraguay's publicity machine is awash with facts and figures about the Itaipú hydroelectric project – the world's second-largest dam (only China's Three Gorges Dam is bigger). Itaipú's generators supply nearly 80% of Paraguay's electricity and 25% of Brazil's entire demand. While project propaganda gushes about this human accomplishment, it omits the US$25 billion price tag and avoids the mention of environmental consequences. The 1350-sq-km, 220m-deep reservoir drowned Sete Quedas, a set of waterfalls that was larger than Iguazú.

Free tours leave from the visitors center, north of Ciudad del Este, near the town of Hernandarias; passports are required. Any bus marked 'Hernandarias' (3500G, every 15 minutes) passes in front of the dam. A taxi will charge around 60,000G one-way or 90,000G return, including waiting time.