Itaipu Dam is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. It has the second-largest hydroelectric power station in the world regarding instantaneous generating capacity, but it generates nearly an equal amount of energy during the course of a year.

Itaipu is actually four dams joined together – from the far left, an earth-fill dam, a rockfill dam, a concrete buttress main dam, and a concrete wing dam to the right. Itaipu Dam produces six times as much power as the Hoover Dam and is 10 times as heavy and 18 times the size. On May 5, 1984, the first generation unit started running and the last two of these started running in the year 1991. In 1994, the American Society of Civil Engineers elected the Itaipu Dam as one of the Seven Wonders of the Modern World. In 1995, the magazine Popular Mechanics published the results. The total length of the dam is 7,235 metres (23,737 ft). The crest elevation is 225 metres (738 ft).

Its construction had social and environmental impacts: when construction of began, approximately 10,000 families were displaced and the Guaíra Falls (which disappeared) were a barrier that separated freshwater species in the upper Paraná basin from species found below it, and the two are recognized as different ecoregions. After the falls disappeared, many species formerly restricted to one of these areas have been able to invade the other, causing problems associated with introduced species.

More Info: