Until then, their existence remains a mystery.
To this day, the burial site of Alexander the Great has never been found.
And while some people may seem content with the story as it stands, our view is that there exist countless mysteries, scientific anomalies and surprising artifacts that have yet to be discovered and explained.
These line were etched into the ground over a period of 3,000 years by indigenous people living near the volcano Sajama.
The Hypogeum of Hal Saflieni in Malta is a UNESCO World Heritage Site which is believed to be the oldest prehistoric underground temple in the world.
Like many prehistoric artifacts, the cultural meaning may never be known.
Sometimes they offer a night show with lights.
Due to haze and smoke, it was a disappointment.