Have you lost your keys? The remote control? An umbrella? A holy grail? ...you can look for them in the Eiffel Tower or the Roman Coliseum, maybe they flew to the Great Wall of China or are in some corner of Machu Picchu, use your mouse to wallow the world and do not leave any corner without checking until you find your lost things.
If you find some hidden object wait till the music ends or check your medal room at main menu.
if you need any help check this link https://munguiavideojuegos.blogspot.com/2017/09/objetos-perdidos-donde-en-el-mundo.html