- The Lost City of Atlantis is an ancient mystery. The city was believed to have sunk underwater around 9,600 BCE. The Greek philosopher Plato wrote about it, saying it was a large island near Spain. Many theories exist about its possible location, including Africa, Greece, and Antarctica.
- Hessdalen Lights are unexplained lights seen in the sky over a Norwegian valley. They appear and disappear, move in different directions, and can be as big as cars. Scientists still don’t know what causes them.
- The Baghdad Battery is a 2,000-year-old clay jar found near Baghdad. It has a metal stick inside and can produce electricity when vinegar is added. The exact purpose of the battery is unknown, but it may have been used to stick gold onto silver.