Guaíra Falls
Guairá Falls (, ) were a series of immense waterfalls on the Paraná River along the border between Paraguay and Brazil. The falls ceased to exist in 1982 when they were inundated by the impoundment of the Itaipu Dam reservoir. While published figures vary, ranging from per second to per second, Guaíra's flow rate was among the greatest of any then-existing falls on Earth. The falls comprised 18 cataracts clustered in seven groups—hence their Portuguese name, "Sete Quedas" (Seven Falls)—near the Brazilian municipality of Guaíra, Paraná and Salto de Guairá, the easternmost city in Paraguay. The falls  were located at a point where the Paraná River was forced through a narrow gorge. At the head of the falls, the river narrowed sharply from a width of about to . The total height of the falls was approximately , while the largest individual cataract was high. The roar of the plunging water could be heard from away. Submergence. A tourist attraction and a favorite of locals, the falls were completely submerged under the artificial lake created by the Itaipu Dam upon its completion in 1982. The building of the dam, authorized by a 1973 bilateral agreement between the Paraguayan and  Brazilian regimes of the time, marked a new era of cooperation between the countries, both of which had claimed ownership of Guaíra Falls. As construction of the Itaipu Dam progressed, thousands of visitors flocked to the area to see the falls before they disappeared forever. Disaster struck on January 17, 1982, when a suspended footbridge affording access to a particularly spectacular view of the falls collapsed, killing dozens of tourists. Brazilian poet Carlos Drummond de Andrade wrote a poem expressing his dismay at the destruction of Guaíra Falls. Set in large type, the poem filled an entire page in the  Jornal do Brasil newspaper:Here seven visions, seven liquid sculptures vanished through the computerized calculations of a country ceasing to be human in order to become a chilly corporation, nothing more. A movement becomes a dam. Earlier, as the waters began to rise, a demonstration took place, as hundreds of people gathered to participate in a "guarup", an indigenous ritual in memory of the falls. The inundation took only 14 days, occurring during the rainy season when the level of the Paraná River was high. By October 27, 1982, the reservoir was fully formed and the falls had vanished. Some  sources state the Brazilian government later dynamited the submerged rock face of the falls, to promote safer navigation on the river, but the factuality of the statement is unclear. The director of the company that built the dam was quoted as saying, "We're not destroying Seven Falls. We're just going to transfer it to Itaipu Dam, whose spillway will be a substitute for [the falls'] beauty".