Beach Policeman, Potomac River, 1922. (Photo by National Photo Company/Colorized by Patty Allison)

The sun streaks through the fall foliage at sunrise along the Potomac River in Arlington, Va., Wednesday, November 4, 2015 on a warm fall day in the nation's Capitol area. (Photo by J. David Ake/AP Photo)

Stumpy the mascot dances near “Stumpy” the cherry tree at the tidal basin in Washington, Tuesday, March 19, 2024. The weakened tree is experiencing its last peak bloom before being removed for a renovation project that will rebuild seawalls around Tidal Basin and West Potomac Park. (Photo by Nathan Ellgren/AP Photo)

US Army Parachute Team Golden Knights perform a precision drop to commemorate the 50th anniversary of the end of the Vietnam War, above West Potomac Park in Washington, DC, USA, 11 May 2023. The performance is one of many activites being held on the National Mall over three days to honor Vietnam War veterans and their families and to commemorate the 50th anniversary of when the last US combat troops left South Vietnam in 1973. (Photo by Michael Reynolds/EPA/EFE)

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.

A Hindu holy man or Sadhu walks back to his ashram after taking a dip at Sangam, confluence of Ganges river, Yamuna river and mythical Saraswati river in Allahabad, India, Thursday, August 4, 2016. (Photo by Rajesh Kumar Singh/AP 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)

Dancers pose for a photo as they prepare during Festival Cilung or “Love the Environment” Festival, where boats made from recycled materials, mostly plastic bottles, sail on the Ciliwung River, one of the most polluted rivers in the world, to raise public awareness about river pollution, in Jakarta, Indonesia, on September 28, 2025. (Photo by Willy Kurniawan/Reuters)