The world below
In folk cultures, myths or legends, an underground world deep inside the Earth is a quite popular concept.
There are countless mysterious caves on Earth that are said to lead to the hollow world.
Famous theories
There have been astronomers and mathematicians who support the Hollow Earth theory.
He believes that the Earth we live on does not have a solid core inside, but has many layers of empty space interspersed with solid space.
Theories also suggest that inside the Earth there is a core filled with lava, considered a `second sun`.
Another scientist who supports this hypothesis is Leonhard Euler, a mathematical genius in the 18th century. He argued that in addition to being hollow, the Earth also has two large holes corresponding to the two poles, which is also the shape
Another bolder theory, by cult leader Cyrus Teed, is that we ourselves are living in a Hollow Earth.
Something underground
Modern belief in the Hollow Earth theory can be somewhat ambiguous, because of the mixture of scientific research and works of fiction.
In famous works, influencing the modern concept of the Hollow Earth, below us is a world of some race more advanced than humans.
There are other stories that tell of a forgotten people, forests and prehistoric animals of enormous size.