Itaipú Dam

Itaipú is a hydroelectric dam on the Paraná shared between Paraguay and Brazil and for decades the largest power station on earth by output, still the second after Three Gorges. It supplies most of Paraguay's electricity and a substantial share of Brazil's. The wall is nearly eight kilometres long and two hundred metres high, and guided tours run inside to the turbine hall. On Friday and Saturday nights the whole face is floodlit. A biological reserve and a small zoo on the Paraguayan bank take animals rescued when the reservoir filled. Tours are free but have to be booked in advance with a passport.