As the name suggests, 7 Wonders: Wonder Pack includes new wonders for use with the 7 Wonders base game, with the wonders in question being:
The Great Wall of China, with the owner being able to build the stages of this wonder in any order (since the wall is, of course, a long horizontal wonder and not a primarily vertical one)
Stonehenge, with the amount of stone you have being important during its construction
Abu Simbel, in which leaders can be buried and mummified for bonus points