Have you ever made a wish and tossed a coin into a fountain? Bet you didn't take a moment to consider where exactly all that cold, hard cash goes after you drop it.

If you thought it stayed there for all of eternity, that's cute. You're wrong.

In fact, with millions of tourists frequenting some of the world's most famous fountains, the coins would pile up pretty quickly if the cities didn't do something about it.

Depending on the city and the fountain, collected coins either contribute to fountain upkeep, charity or public service. The change from fountains in New York City go towards the fountain upkeep.

The Trevi Fountain in Rome receives so many coins from tourists that it has to be cleaned every night. The BBC reports that workers collect up to $4,000 USD in loose change daily. In a year, the coins from the Trevi Fountain add up to about a million dollars!

So, the next time you toss a coin and make a wish, you can feel good about knowing that your small contribution adds up in a big way!

[Source: Smithsonian / The Atlantic / BBC ]