Some are already included.
Possible additions for future updates:

Australia: Ayers Rock (Uluru) / Sydney Opera House
Brazil: Christ the Redeemer
Canada: Niagara Falls
China: Great Wall of China
Egypt: Great Pyramid of Giza
Germany: Neuschwanstein Castle
Greece: Acropolis
India: Taj Mahal
Japan: Shibuya
Mexico: Chichen Itza
Peru: Machu Picchu
Russia: Saint Basil's Cathedral
South Africa: Table Mountain
Tanzania: Mount Kilimanjaro
United Kingdom: Big Ben / Tower Bridge
U.S.A.: Times Square / WTC Twin Towers / Hollywood sign

Comment to suggest more!