The Hollow Earth Theory

Way before modern times they thought the world was flat. But, still to this day there are believers that our world is actually hollow. 

Although this theory is often rubbished as nothing more than fantasy. Some are still persistent in their belief that it the world actually has an interior void. 

This is made worst due to the reported claim that the "US Government is covering up the secret hole – a theory they say is supported by the fact aircraft are blocked from flying over the North Pole" 

There is also the conspiracy theorists who are particularly fond of Youtube such as secureteam10.

“Every single satellite image that we have of the North Pole shows a massive hole or a black out hole put there to hide whatever’s underneath.”

 
However there is scientific evidence which contradicts these wild claims. This includes the important fundamentals of our density, the way gravity works and seismic waves.  

But like any good conspiracy...why would you cover this one up? Is what lays in the centre of the earth too unbelievable to fathom? Does it dispute everything our lives are based on? 

What do you think?