But the components that led to their formation go back hundreds of millions of years. At other times, a mere quarter-million gallons flow over the Falls, the minimum prescribed by a 1950 treaty.HOW WERE THEY CREATED?Geologically speaking, the Falls at Niagara are veritable new-borns; they are only about 12,000 years old. Most of the water is diverted to a pair of hydro-electric plants, one of which may have precipitated Thursday’s blackout in the US. The authorities control the amount of water over the Falls, and tailor it to the number of visitors. The maximum flow of half a million gallons per second occurs between 8am and 10pm from April to mid-September, from mid-September to 31 October, the hours are 8am-8pm.

From the Canadian side – which gives the best view – they are, respectively, the American Falls, the Bridal Veil Falls and the Canadian Falls. Ninety per cent of the water flows over the Canadian Falls, also known as the Horseshoe Falls.Collectively, the Falls may look spectacular – but the flow of water is between one-quarter and one-half of what would naturally occur. The most populous cities in both countries are relatively close; New York is 446 miles away by road, and Toronto is just 83 miles.WHAT ARE THEY?Niagara Falls comprise three adjacent waterfalls on the Niagara river at the point where it widens to 1,060 feet and plummets 167 feet. But most visitors will spend their time at one or both of the towns named Niagara Falls on each side of Niagara Falls.The nearest cities to the Falls are Buffalo in the US (23 miles) and Hamilton in Canada (40 miles).

You might also be muddled by the high number of places called Niagara. You can visit the US town of Niagara, upstream on the Niagara River; the Canadian town of Niagara-on-the-Lake; and two airports named Niagara on the US side alone: Niagara Falls International and Buffalo-Niagara International. The water from four of the Great Lakes is funnelled into the fifth at the point where the Canadian province of Ontario squeezes against New York State. The frontier between the US and Canada runs north-south here, with Canada to the west, which some visitors find geographically confusing.

Yet the natural spectacle transcends the messy handiwork of man. And because many of the visitors are only at Niagara for the day, the hours after dawn and before sunset are relatively tranquil – apart from the constant roaring of the Falls.WHERE ARE THEY?Along the Niagara River, between Lakes Erie and Ontario. The popularity of this scenic wonder has encouraged the building of some undecorous hotels and garish places to eat and drink. NIAGARA: A TACKY TOURIST TRAP?

NIAGARA: A TACKY TOURIST TRAP?
Most certainly. Every two seconds, one million gallons of water plummet over Niagara Falls – and every month, on average, a similar number of tourists turn up to see the spectacle.