Trevi Fountain
Here it is: Fontana di Trevi as featured in Fellini's 'La Dolce Vita'.
This is one of the best known spots in Rome, with water supplied from one of the oldest aqueducts.
The custom is to throw a coin into the fountain over your shoulder while facing away from it. This ensured that you will return to Rome. But toss a second coin and you'll fall in love with an Italian. Toss a third and you will marry that Italian!