Iguazu Falls are located where the Iguazu River tumbles over the edge of the Paraná Plateau, 23 kilometres upriver from the Iguazu’s confluence with the Paraná River. Numerous islands along the 2.7-kilometre-long edge divide the falls into many separate waterfalls and cataracts, varying between 60 to 82 metres high. The number of these smaller waterfalls fluctuates from 150 to 300, depending on the water level. Approximately half of the river’s flow falls into a long and narrow chasm called the Devil’s Throat. The Devil’s Throat is U-shaped, 82 metres high, 150 m wide, and 700 m long.