TEOTIHUACAN The ruins of the ancient Mexican capital, Teotihuacan, remain a mystery to scientists to the present day. Little is known about the former historic rise and fall of this first major city on the American continent. During its heyday, Teotihuacan extended over an area of more than 20 square kilometres and ruled over a city-state that was larger than that of Ancient Rome. It is believed that the origins of this impressive city date back as far as the second century B.C. Four large platforms surround the Citadel, the administrative centre of the city. On the opposite side is the magnificent and impressive Quetzalcoatl Temple, which is adorned with several reliefs. The huge, towering Sun Pyramid is one of the main landmarks. Overawed by the magnificent structure, the Aztecs described it as, "The place where one becomes god" – and it is indeed a magnificent and fascinating sight to behold. Global Treasures - History's Most Protected Monuments - Heritage is our legacy from the past, what we live today, and what we pass on to future generations. Our cultural and natural heritage are both irreplaceable sources of life and inspiration. Places as unique and diverse as the wilds of East Africa's Serengeti, the Pyramids of Egypt, the Great Barrier Reef in Australia and the Baroque cathedrals of Latin America make up our world's heritage. Join us as we explore one of these protected monuments.