Prepare the cherry base by placing pitted cherries in a blender or food processor. Pulse until completely pureed and smooth, about 30-45 seconds.
Strain the cherry puree through a fine-mesh strainer into a bowl, pressing with a spoon to extract as much liquid as possible. Discard the solids or save for another use.
Mix the flavor base by combining the strained cherry juice, fresh lime juice, honey or maple syrup, and lime zest in a pitcher. Stir until the sweetener is completely dissolved.
Chill the mixture in the refrigerator for at least 30 minutes to allow the flavors to meld together.
Assemble each mocktail by filling glasses halfway with ice, then adding about 1/4 cup of the cherry-lime mixture.
Top with sparkling water, pouring slowly to maintain carbonation. Aim for a ratio of 1 part cherry mixture to 2 parts sparkling water.
Gently stir each glass once or twice to combine the ingredients without losing too much fizz.
Garnish with fresh cherries and lime wheels on the rim of each glass. Add a sprig of mint if desired.