1) 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.

2) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

3) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

4) Cyclones can cause widespread damage through high winds, heavy rainfall, and flooding. They can also generate tornadoes and trigger landslides.