Fresh cherries, lime juice, and sparkling water make a very refreshing summer drink!
Place the sugar, lime juice, and the pitted cherries in a blender. Blend on high speed until smooth.
If you like, you can strain the cherry mixture through a fine mesh sieve, to remove any small pieces of cherries. I didn't do this, and didn't find the bits of cherries bothersome.
Divide the cherry lime syrup evenly among four glasses with ice. Pour about 9 ounces of sparkling water into each glass and stir. Top each glass with a cherry if you like.
Leftover cherry syrup can be stored in the refrigerator overnight, but it may discolor slightly.