Brazil–Paraguay border
Brazil took Paraguayan land along this border after Paraguay’s catastrophic defeat in the War of the Triple Alliance. On the Paraná river the two countries later built one of the world’s largest dams together, whose reservoir drowned the great Guaíra Falls.
Written from cited sourcesLast checked 29 September 2026Suggest a correction
See it on the globe:Brazil →Paraguay →
After the war
Paraguay had quarrelled with Argentina and Brazil over borders and tariffs for years before its dictator, Francisco Solano López, went to war with Brazil in 1864. Argentina, Brazil and Uruguay allied against it in 1865, and the war ended with López’s death on 1 March 1870.[1]
It was the bloodiest conflict in Latin American history. Paraguay’s population fell from about 525,000 to about 221,000 by 1871, of whom only about 28,000 were men. Argentina and Brazil annexed about 140,000 km² of Paraguayan territory; Brazil enlarged its province of Mato Grosso, and the two allies occupied Paraguay until 1876.[1]
Itaipú and the lost falls
On the Paraná, the border river in the south, the Guaíra Falls poured through a narrow canyon: 18 falls with a total drop of about 114 metres, audible 32 km away and probably the greatest volume of falling water in the world.[4]
Brazil and Paraguay built the Itaipú Dam there as a joint venture between 1975 and 1982. Its complex of dams and spillways curves almost 8 km across the river, its turbines can generate 14,000 megawatts, and its reservoir, stretching about 160 km north, completely submerged the Guaíra Falls.[2][4]
A border town
Ciudad del Este, founded in 1957 on the Paraná, grew into Paraguay’s second city thanks to trade with Brazil, symbolised by the 500-metre Friendship Bridge to Foz do Iguaçu, opened in 1964, and to the nearby dam. Its economy rests on retail, Brazilian tourists and contraband trade in electronics and firearms.[3]
Timeline
1864
War begins
Paraguay goes to war with Brazil.[1]
18701 March 1870
War ends
López is killed; Brazil later enlarges Mato Grosso with Paraguayan land.[1]
1876
Occupation ends
Argentine and Brazilian forces leave Paraguay.[1]
1964
Friendship Bridge
A bridge links Ciudad del Este and Foz do Iguaçu.[3]
1975–82
Itaipú built
The joint dam is built on the Paraná.[2]
1982
Falls drowned
Itaipú’s reservoir submerges the Guaíra Falls.[4]
More borders
Sources
- [1]War of the Triple Alliance · Encyclopaedia Britannica (Wayback Machine copy)
- [2]Itaipú Dam · Encyclopaedia Britannica (Wayback Machine copy)
- [3]Ciudad del Este · Encyclopaedia Britannica (Wayback Machine copy)
- [4]Guaíra Falls · Encyclopaedia Britannica (Wayback Machine copy)
Map geometry from Natural Earth via world-atlas. See credits.