a link from the pages:

Symmes spent his entire life advocating his hollow-Earth theory on the literary circuit and gained quite a few followers. True, those were simpler times, but they sure as hell weren’t that simple — the hollow-Earth theory was already known to be utter bullshit. What Symmes proposed was the 1800s equivalent to sending people to the moon to find cheese. He wanted to mount an expedition to silence his critics and also to conduct trade with the mole people.

Unfortunately for Adams, the Mole People and the Crab People went to war shortly thereafter. The resultant conflict came to be known as “America’s Secret Underground Vietnam.”

Adams approved the expedition, which would venture to the North Pole, where the entrance to the underworld was supposedly located. Unfortunately, the crazy road trip never came to be, as Adams left office before anything could be done. As luck would have it, his successor, Andrew Jackson, was a man who believed the world was flat. Naturally, Jackson promptly canceled the expedition and along with it, dashing of contacting mole people.

Read more: http://www.cracked.com/article_18945_6-presidential-secrets-your-history-teacher-didnt-mention_p2.html#ixzz1A5JF4Xkt

You now, I’ve honestly never heard of the hollow-earth theory. Wonder if there are still any believers? :)