Bring water, sugar and cherries to a simmer and cook just until sugar is dissolved and cherries have given off their color and flavor (about 10 minutes).
Pour the simple syrup into a pitcher along with the lime juice, and 3 cups of water (adding an additional cup of water if necessary). Refrigerate for 1 hour or until ready to serve.
Serve the limeade over ice, garnished with slices of lime and a cherry from the syrup.
Notes
For garnishes you can also soak some extra pitted cherries in sugar and honey for 30 minutes (or up to a day) and use these to top off each drink. For adding liquor, add a 1/2 shot to each drink of either vodka or amaretto.