Each year, an average of ______ people visit the Niagara Falls.

Niagara Falls are a major attraction for people everywhere. Each year, an average of 12 million people visit the site some call one of the world’ s natural wonders.
   There are two falls: the Canadian or Horseshoe Falls, and the American Falls. They are separated by Goat Island, on the American side of the border.
   The Horseshoe Falls are 54 meters high and extend for 675 meters in the horseshoe shape that gives the Falls its name. The Horseshoe Falls are more impressive than the American falls. Some visitors find it curious that the falls are "turned off" in the early morning; at the time, most of the water is diverted to hydroelectric plants.
   The first European visited the falls toward the end of the seventeenth century. The tourist industry began about 125 years later. And very quickly, Niagara Falls became a favorite site for honeymooning couples. A circus atmosphere soon followed that featured high-wire acts over the falls and other stunts. The one that is best known is the attempt to go over the falls in a barrel, completed a number of times, sometimes successfully and sometimes not.
   Of course, there’ s more to Niagara Falls than stunts and tourism, it is worth remembering that the incredible drop in water level made the Falls an ideal place for hydro-electric development. The first generating station opened in 1906. And it was partly because of the availability of inexpensive electric power that this region became one of the most industrialized regions in Canada.