In 1968, Erich van Daniken published the book "Chariots of the Gods". This bestselling book tells of visitors from other planets to Earth in ancient times. Most scientists have expressed great doubts about the author's ideas. For example, Van Daniken suggested that gold artifacts from Incan culture represented otherworldly spacecrafts and that long stretches of land may have been prepared as runways upon which alien ships could land. Van Daniken also suggested that aliens trapped on Easter Island, off the coast of Chile in the Pacific Ocean, carved strange and mysterious stone statues found there. These statues seem too large to have been created with the archaic tools that the ancient humans had. What is more, the stone statues bear no resemblance to the island dwellers or their ancestors. Van Daniken also proposed that the gigantic statues may have served as a call for help to fellow aliens searching from the skies for their stranded friends.
Some people think that extraterristrials built the Great Pyramid (above). Even with today's technology, the pyramid could not be duplicated.