South Korean soldiers participate in a winter river crossing operation in preparation for a possible North Korean attack on February 8, 2012 in Yeoju, South Korea. The Korean peninsula is the world's last Cold War frontier as stalinist North Korea and pro-western South Korea have been technically at war since the 1950-53 conflict. (Photo by Chung Sung-Jun/Getty Images)

In this photo taken Wednesday, April 30, 2014, a dragonfly sits on the nose of a Gharial, rare crocodile-like creatures, in the River Chambal near Bhopepura village in the northern Indian state of Uttar Pradesh. The narrow 250-mile stretch of the Chambal is a place of crocodiles and jackals, of river dolphins and the occasional wolf. Hundreds of species of birds, storks, geese, babblers, larks, falcons and so many more, nest along the river. Endangered birds lay small speckled eggs in tiny pits they dig in the sandbars. Gharials, rare crocodile-like creatures that look like they swaggered out of the Mesozoic Era, are commonplace here and nowhere else. (Photo by Altaf Qadri/AP Photo)

The Mike O'Callaghan–Pat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately 30 miles (48 km) southeast of Las Vegas, Nevada, and carries U.S. Route 93 over the Colorado River.

Iguazu Falls are waterfalls of the Iguazu River on the border of the Brazilian state of Paraná and the Argentinian province of Misiones. The falls divide the river into the upper and lower Iguazu. The Iguazu River rises near the city of Curitiba. It flows through Brazil for most of its course. Below its confluence with the San Antonio River, the Iguazu River forms the boundary between Argentina and Brazil.

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

People wade through a flooded path near Sangam, the confluence of the Ganges, Yamuna and mythical Saraswati rivers after the water level of river Ganges and river Yamuna rose, in Allahabad on October 14, 2022. (Photo by Sanjay Kanojia/AFP Photo)

A devoteetakes a holy dip in the River Ganges on Ganga Dussehra festival in Prayagraj, India, Tuesday, May 30, 2023. Hindus across the country celebrate Ganga Dussehra by worshiping the River Ganges, which is considered as the most sacred and the holiest river. (Photo by Rajesh Kumar Singh/AP Photo)