Photograph by Yvonne Baur, My Shot
Waterfalls occur when flowing river water drops abruptly and vertically. The water falls as a result of an edge of a cliff or plateau, or the edge of a hanging valley formed under glacial conditions. As a stream grows older, the waterfall usually erodes the edge and the cliff loses height until it eventually becomes a series of rapids and finally disappears.
Niagara Falls pictured above.
Photograph by Jay Stockhaus, My Shot
Waterfalls are big tourist attractions. Hanging Lake Trail, located in Glenwood Canyon in Colorado, sees more than 80,000 hikers per year.
Photograph by Alison Wattles, My Shot
Yosemite Falls, one of the world's tallest waterfalls, is made up of three separate falls: Upper Yosemite Fall, which is 1,430 feet (436 meters); the middle cascades, which is 675 feet (206 meters); and Lower Yosemite Fall, which is 320 feet (98 meters).
Photograph by Troy Lilly, My Shot
The waters of Shay Run reach the Blackwater Canyon's edge and cascade down the canyon's wall as Elakala Falls in Blackwater Falls State Park. The falls are one of the most photographed sites in West Virginia.
Photograph by Stephen Chao, My Shot
The waterfalls of Iceland attract many visitors to this country. Gullfoss, Skógafoss, Seljalandsfoss (pictured), and Svartifoss are some of the more popular sites to visit in Iceland.
Photograph by Jenny Nguyen, My Shot
Overlooking the Mississippi River, Minnehaha Park is one of Minneapolis’ oldest and most popular parks, attracting over 850,000 thousand visitors annually. The 193-acre (78-hectare) park features a 53-foot (16.15-meter) waterfall.
Photograph by Todd Mitsuhata, My Shot
Iguazu Falls is shared by both Brazil and Argentina. In guarani language, the term "Iguazú" means "great waters." This water smoothly runs until it reaches a series of faults and a 262-foot (80-meter) canyon in Devil's Throat, where the water drops and produces a thundering sound.
Photograph by: Kamil Tamiola, My Shot
The Tatra valleys in Slovakia and Poland have cascading waterfalls. This waterfall is mostly frozen (pictured above).
In Niagara Falls, the flow of water actually stopped completely for a few hours on March 29, 1848 because of an ice jam in the upper river. The Falls did not actually freeze over, but the flow was stopped sufficiently to allow people to walk out and recover artifacts from the riverbed.