The Great Pyramid at Giza
Cairo, Egypt
Noted for being the only surviving member of the Seven Ancient Wonders of the World, the Great Pyramid is the largest of the 3 pyramids built in the ancient city of Giza, now part of greater Cairo, Egypt. The pyramid is believed to have been built around 2560 B.C. as a tomb for the Egyptian Pharaoh Khufu, and likely took 20 years to construct. (Egyptologists argue over man-power numbers, and estimates have ranged from 14,000 to 360,000 men). When built, the pyramid measured nearly 480 feet high, with the sides each measuring about 755 feet long. In addition, each side is oriented with one of the cardinal points (north, south, east and west). Nearly 2.3 million blocks of stone, each weighing approximately 2 tons, comprise the pyramid. The pyramid remained the world's tallest building for 4 millennia after it was built.
Hanging Gardens of Babylon
Al-Hillah, Iraq
The Hanging Gardens of Babylon are said to have been built by Nebuchadnezzar II, a ruler of Babylon, around 600 B.C. Though historians often debate the actual existence of the gardens, because there's no physical evidence and Babylonian documents never mention them (Greek scholars first described the gardens), accounts state that the gardens consisted of vaulted terraces raised above one another and supported on pillars -- in other words, an artificial rising mountain of gardens. The terraces were filled with dirt and planted with trees and flora, which were said to hang over the sides. The amazement over the gardens stems from what would have been an extraordinarily complicated irrigation system, which brought water from