As for what happens to coins in other fountains and wishing wells, you’ll sometimes run across a sign saying “proceeds go to…” which makes it pretty easy to figure out where your coins end up. Lacking a sign, however, it’s most likely that your coin will be collected and donated to a charity, or perhaps put toward the upkeep of a historic building or a zoo. Even the coins thrown in fountains owned by private businesses tend to be donated rather than kept by the business itself.

Source::  Today I found out