Heat the sugar and one cup of water in a small saucepan on low until sugar is dissolved completely.
The sugar will go from cloudy to clear once it is dissolved.
Add four cups of cold water to a pitcher.
Pour the simple syrup made with the sugar and water into the pitcher.
Add the freshly squeezed lemon juice.
Puree the watermelon in a food processor or blender
Strain the watermelon puree with a fine mesh.
You should be left with 4 cups of watermelon juice.
Add the Watermelon strain puree to the pitcher.
Break up 6 to 8 mint leaves and add it to the pitcher.
Stir well and enjoy or refrigerate.