Conspiracy theorists believe that NASA, together with the world government, is trying to cover-up a massive hole at the North Pole, which they believe to be a passage way to an inner earth that is complete with vegetation, animals, human civilizations and inner sun.

In a recent YouTube video posted by SecureTeam10, the conspiracy theorists group provided series of images and videos that was allegedly taken down by NASA revealing a giant, stable hole in the North Pole. According to them, NASA is a part of worldwide cover-up to hide the, what they claim to be, an entrance to inner earth.

The hollow earth theory was first proposed by Edmund Halley, a distinguished English scientist who studied the comet that bears his name, in 1692, explaining that the Earth consists of a hollow shell about 800 km (500 miles) thick, two inner concentric shells and an innermost core.

John Symmes, an American army officer, followed through Halley and proposed the "theory of concentric spheres and polar void" in 1818.

According to the report from the Inquisitr, Symmes planned to an expedition to explore the hollow with the help and funding from the government. However, he didn't get the help he needed and died in 1829 without achieving his lifelong dream.

Not soon after, many hollow earth theorists planned expeditions to explore the massive hole. However, due to some rare coincidences, some members of their expedition team died in an accident.

Mirror reported that Polar explorer Admiral Richard E Bird detailed in his diary his success of reaching inner Earth. According to him, he entered the hole and travelled 1,700 miles among mountains, vegetations, lakes, civilization and mammoth-like monster animals.

During the Nazi regime, the hollow earth theory is very much celebrated. According to the video, Adolf Hitler even ordered a research journey for a similar opening in the Antarctica. According to an article in Crystal Links, there are theories going around that Hitler with his men have found a refugee by entering the giant hole leading to inner Earth and up until now they are still enjoying their safe haven inside.