2) Ancient Pyramids in Giza, Egypt
Khafre (l.) and Khufu (r.) are two of the three ancient Pyramids in Giza, Egypt. Khufu is the biggest, consisting of more than 2 million stones with some weighing 9 tons. The Pyramids, built as elaborate tombs for divine kings, date back to 2,550 BC. Modern Egyptologists believe that the Pyramids are made from stones dragged from quarries and, despite ancient Greek testimony, were built predominantly by skilled craftsmen rather than slave labor.