Combine water and sugar in small saucepan; add halved cherries. Bring mixture to boil; reduce heat and simmer 5 minutes. Remove from heat and cool to room temperature. Strain syrup into container with tight fitting lid; discard cherries. Refrigerate syrup until cold.
Fill a tall 12 to 16-ounce glass with ice. Pour 1/4 cup lemon juice and 1/3 cup syrup over ice and top with club soda. Garnish with cherries and mint.