How and why are the wonders of the world selected?

Why are there seven world wonders in the ancient world?

• I would really like to know why are there seven world wonders, and not any other number from one to ten. For example in the ancient world among the first list of world wonders was the Ishtar Gate, the eight gate to the inner city of Babylon and in the sixth century AD it was replaced with the Lighthouse of Alexandria. Why wasn't the Lighthouse of Alexandria just added to the list instead of removing the Gate of Ishtar? Don't get me wrong I like all of them but my question is what's with the number 7? I would really like to know so If anybody knows, please share it. Thank you

• Answer:

  Various lists of the Wonders of the World have been compiled from antiquity to the present day, to catalogue the world's most spectacular natural wonders and manmade structures. The Seven Wonders of the Ancient World is the first known list of the most remarkable creations of classical antiquity, and was based on guide-books popular among Hellenic sight-seers and only includes works located around the Mediterranean rim. The number seven was chosen because the Greeks believed it to be the representation of perfection and plenty. Many similar lists have been made. The historian Herodotus (484 – ca. 425 BCE), and the scholar Callimachus of Cyrene (ca. 305 – 240 BCE) at the Museum of Alexandria, made early lists of seven wonders but their writings have not survived, except as references. The seven wonders included: Great Pyramid of Giza Hanging Gardens of Babylon Statue of Zeus at Olympia Temple of Artemis at Ephesus Mausoleum of Maussollos at Halicarnassus Colossus of Rhodes Lighthouse of Alexandria The earliest lists had the Ishtar Gate as the seventh wonder of the world instead of the Lighthouse of Alexandria. The list known today was compiled in the Middle Ages—by which time many of the sites were no longer in existence. Today, the only ancient world wonder that still exists is the Great Pyramid of Giza.