Like Stonehenge, many mysteries surround the construction of these three pyramids, which are part of a mausoleum complex. The Great Pyramid of Giza, the best-known of the group standing outside of Cairo, is the only one of the ancient Seven Wonders of the World that also graces our list. Finished around 2,560 BC, the 481-foot creation (now shorter due to erosion) was the tallest man-made structure in the world for 38 centuries until the completion of Lincoln Cathedral in 14th-century England. How were these made? Were space aliens needed to cut, move and stack the millions of stones, some weighing 88 tons? Does some powerful force emanate from them today? Hop on a camel or hail a taxi and go judge for yourself.