The mystery is called the Nazca Lines.
It is located in the Nazca Desert, in southern Peru.
It is believed that they were made between 500 B.C. and 500 A.D.
They are huge drawings on the ground, and no one knows exactly how or why they were made.
There are some ideas about why they might have been created, for example:
It must have been a place for religious ceremonies,
it must have been a giant astronomical calendar,
or it might have been a way to ask the gods for water in the desert.
There are also ideas that don’t make sense, for example:
It can’t have been made just for fun,
it can’t have been built with modern machines,
and it can’t have been made by giants.
The Great Pyramid of Giza is one of history's biggest mysteries. It was built around 2500 BC, and no one knows exactly how they moved such huge stones. It must have been an amazing engineering achievement. Some say it was built by aliens, but it can't have been true.
