In a pitcher, muddle cherries until juices release. If using syrup, add directly.
Pour in lemon juice and sugar. Stir until the sugar dissolves.
Add cold water and mix well.
Taste and adjust sweetness if needed.
Strain for a smoother texture, or leave fruit pieces in for rustic style.
Add ice cubes and garnish with lemon slices and cherries.
For sparkling cherry lemonade, top with chilled sparkling water just before serving.