Before the construction of the Itaipu Dam, the Guaíra Falls, also known as Sete Quedas, were among the most powerful waterfalls in the world. Located on the Paraná River, near the border between Brazil and Paraguay, the falls were not actually seven but eighteen individual drops, grouped into seven distinct clusters. The river flowed through a narrow gorge where its width dropped from 380 meters to just 60 meters, creating a total drop of 114 meters. The largest waterfall reached 40 meters in height, and the sound of the water could be heard up to 30 kilometers away. While some sources claim the flow rate reached as high as 50,000 cubic meters per second, others estimate an average of 13,000 cubic meters per second. Regardless of the exact number, the Guaíra Falls were among the highest-volume waterfalls ever recorded. A suspension bridge once provided visitors with a view of one of the falls, but on January 17, 1982, its steel cables gave way under the weight of overcrowded tourists. Brazilian sources report 32 deaths, while the New York Times estimated the toll at around 40. The exact number remains uncertain, but the tragedy highlighted the dangers of poorly maintained infrastructure. This incident occurred nine months before the falls themselves were submerged by the construction of the Itaipu Dam, which would permanently alter the landscape. On October 13, 1982, the dam's gates closed, and the Paraná River began to rise rapidly due to the rainy season. Within two weeks, the reservoir was full, and the eighteen waterfalls vanished beneath the water. Before their disappearance, local residents and indigenous communities gathered for a guarup, a traditional funeral ceremony usually held for the deceased. In this case, the ritual was a tribute to the lost landscape, symbolizing the end of a natural wonder that had shaped the region for millennia. The city of Guaíra, once home to 60,000 people, has since seen its population halved, as tourism around the falls disappeared with them. The Itaipu Dam was the result of a treaty signed in 1973 between Brazil and Paraguay, aimed at generating hydroelectric power. The dam produces 100 terawatt-hours of electricity annually and provides 75 percent of Paraguay’s energy needs. For years, it rivaled the Three Gorges Dam in China as the world's largest hydroelectric producer. However, the project came at a steep environmental and cultural cost: in just two weeks, it erased a natural wonder that had existed for thousands of years. Today, the site is permanently submerged, unaffected by seasonal changes. While most people have never heard of Guaíra, the Paraná River continues to flow silently at the spot where it once roared with the power of the falls.