A man bathes in an ice hole in the Neva River in St. Petersburg, Russia, Wednesday, January 13, 2021. The temperature in St. Petersburg is –15C ( 5 °F). (Photo by Dmitri Lovetsky/AP Photo)

People watch a brig with scarlet sails floating on the Neva River during the Scarlet Sails festivities marking school graduation in St. Petersburg, Russia, early Saturday, June 25, 2022. (Photo by Dmitri Lovetsky/AP Photo)

The Rossiya (Russia) brig sails along the Neva River during a dress rehearsal of the 2021 Scarlet Sails Festival for school leavers in St Petersburg, Russia on June 25, 2021. (Photo by Peter Kovalev/TASS)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)

A man bathes in an ice hole in the Neva River St. Petersburg, Russia, Wednesday, February 10, 2021. The temperature in St. Petersburg is –15C ( 5 °F). (Photo by Dmitri Lovetsky/AP Photo)

People pass by the floating restaurant “Silver Whale” which partially sank during ice drift on the Neva River in St. Petersburg, Russia, 27 March 2023. Rescuers try to secure it with ropes so that the restaurant is not swept away by the river. The temperatures have reached zero degrees Celsius in the second largest city of Russia. (Photo by Anatoly Maltsev/EPA/EFE/Rex Features/Shutterstock)

People look at smoke and flame rising from the Nevskaya Manufaktura textile factory founded by English merchant J. Thornton in 1841, in St. Petersburg, Russia, Monday, April 12, 2021. The emergencies ministry said the fire had broken out over several floors of the red-brick Nevskaya Manufaktura building on the Oktyabrskaya Embankment of the Neva River. (Photo by Dmitri Lovetsky/AP Photo)

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.