We continue to explore the secrets of the 7 wonders of the world. From the mysterious Maya city Chichen Itza to the breathtaking Colosseum.

Various lists of the Wonders of the World have been compiled from antiquity to the present day, in order to catalogue the world's most spectacular natural features and human-built structures.

The Seven Wonders of the Ancient World is the oldest known list of this type, documenting the most remarkable man-made creations of classical antiquity; it was based on guidebooks popular among Hellenic sightseers and as such only includes works located around the Mediterranean rim and in the ancient Near East. The number seven was chosen because the Greeks believed it represented perfection and plenty, and because it reflected the number of planets known in ancient times (five) plus the Sun and Moon. Many similar lists have been made for other regions of the world or for the entire world, or which include natural wonders instead of man-made structures.