Ancient Aliens is counting down the world's top ten most mysterious monoliths, from a 500-ton stone believed to represent an ancient UFO, to giant statues said to have been created with advanced technology, and ornate pillars that depict otherworldly visitors. Could these extraordinary standing stones provide evidence of extraterrestrial visitation?

Ancient Aliens is counting down ten of the most astonishing--and unexplainable--technologies in history. From mysterious golden orbs discovered in Mexico, to a sacred wooden box that could communicate with the heavens, and an ancient tomb that is said to depict an astronaut, might these sensational artifacts be evidence of otherworldly contact?