AMAZING BUILDINGS OF THE WORLD.
Aya Sofia and Selimiye Mosque (Edirne), Turkey
Mosques of Esfahan and Yazd, Iran. Notably the Masjed-e Shāh
Registan, Samarkand, Uzbekistan
Most of the old city of Jerusalem
Colosseum and old city of Rome, Italy
Rock-hewn: Lalibela's churches, Ethiopia and Petra, Jordan
Honorary mentions.
Vatican City
The Forbidden City (China)
Palace of Versailles (France)
Grand Palace in Bangkok
Temples of Japan (Nara and Kyoto)
Sagrada Familia (Barcelona).
Plus, not really buildings, but extremely impressive: the Eiffel Tower, The Banaue Rice Terraces (Philippines) Baha'i Gardens (Israel), Venice (Italy) and Mount Rushmore (USA).