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

2) The Great Barrier Reef in Australia is the largest coral reef system in the world and is visible from space.

3) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

4) The ancient city of Pompeii was preserved under layers of volcanic ash after the eruption of Mount Vesuvius in 79 AD, providing valuable insights into Roman life.