Yield: makes about 1 quart
In a small sauce pot, combine sugar and 1/2 cup water. Bring to a boil until sugar dissolves. Remove from heat and let cool slightly.
In a blender, combine cucumbers, mint leaves, lemon juice, and slightly cooled simple syrup. Puree until smooth.
Strain through a fine strainer (or cheesecloth). Pour lemonade into a pitcher. Add remaining 2 cups of water. Stir to combine. Keep chilled until ready to serve.