The Great pyramid of Giza
The Great pyramid of Giza, Egypt is one of the master pieces of ancient engineering ever built. It remain the world tallest building ( about 147m or 481feet, far more then The Big Ban tower, Leaning Tower of Pisa and Statue of Liberty) for over 4,000 years. The Great pyramid of Giza is a not mysterious for it colossal size but also for its location at the intersection of longest longitude and latitude lines and its corners which are align with the four cardinal directions of the earth.
Is it possible for the humans in about 2550 B.C to build such a master piece without any modern technology and heavy lifting cranes? Did the builders already know that the Earth was round and its dimensions? Proponents of ancient alien theory claims that extraterrestrial visitors helped humans build the engineering wonder like the Great Pyramid of Giza.