1) The world's tallest waterfall is Angel Falls in Venezuela, with a height of about 3,212 feet (979 meters).

2) The strongest natural material known to man is spider silk. It is stronger than steel and more flexible than nylon.

3) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.

4) A group of flamingos is called a "flamboyance."