Niagara Falls

Niagara Falls owes its fame not to height but to power. Where the Niagara River pours from Lake Erie toward Lake Ontario on the border between the United States and Canada, more than 2,800 cubic metres of water can plunge over the brink every second, the greatest flow of any waterfall in North America. The largest of its three cataracts, the Canadian Horseshoe Falls, throws up a permanent cloud of spray visible for kilometres, a thunder of water that has drawn visitors for two centuries.

At about 57 metres, the falls are modest in height but immense in scale, their crests stretching more than a kilometre across in total. They formed at the end of the last ice age, roughly 12,000 years ago, when retreating glaciers exposed the Niagara Escarpment, and the falls have since eroded steadily upstream as the river undercuts the soft shale beneath its hard cap of dolomite. The three falls, the Horseshoe, the American, and the slender Bridal Veil, are split by islands at the rim of the gorge.

The Indigenous peoples of the region, including the Haudenosaunee, long lived along the river, and the falls became a magnet for European fascination, daredevils, and, by the nineteenth century, mass tourism and a thriving honeymoon trade. The river's tremendous energy was harnessed early for hydroelectricity, and the power stations on both banks still light cities across the region. Carefully managed flows now balance spectacle by day with electricity by night, the falls diverted and restored on a schedule.

• North America
  The third-largest continent, from the Arctic to the tropics located on