There are a lot of "Seven Wonders of the World". Even though it is called "Seven" but there are more than "Seven".
This is divided three categories mainly; The Seven Ancient Wonders, The Seven Midieval Wonders and The Seven Modern Wonders.
First of all, The Seven Ancient Wonders mainly consist of below;
Great Pyramid of Giza
Hanging Gardens of Babylon
Temple of Artemis at Ephesus
Statue of Zeus at Olympia
Mausoleum of Maussollos at Halicarnassus
Colossus of Rhodes
Lighthouse of Alexandria
The only one that still exists in the present time is Pyramid and all the others remain to be mystery forever and that's why they are called Seven Wonders.