The task of compiling the seven wonders of the world for people would have been really a tough one. There were so many marvels to choose from. The task of compiling the list of seven wonders of the world was originally started by around 5th century BC.
We all know the difficulties of old days to travel around places. People had quite tough times in travel and collecting data like these. Imaging traveling by walk or on camels or horses for 100s of miles without a proper place to rest. Of course our generation is blessed to have a large number of hotels and lodges wherever we go. We have aero planes, trains, buses, cars, bikes and what not.
In spite of all such difficulties in travel, People like Herodotus, Callimachus and some others did a good level of research and documentation. They traveled a lot, collected a lot of books, facts and proofs to produce such documentation. But all of them were destroyed when a fire broke out in Alexandria Library. The final list was compiled in the Medieval ages. Alas! such a big loss. What we are left with is only some little maps/atlas and some basic documents from them.
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.
