In a small sauce pan combine water, sugar, and mint leaves.
Bring to a simmer and simmer 5 minutes.
Remove from heat and let cool completely. Strain to remove mint leaves.
Transfer to an airtight container.
Peel your lemons using a pairing knife. If you prefer to use lemon juice rather than whole lemons, see note.
In a blender combine watermelon, lemons, simple syrup, and water.
Use whole juice setting to blend.
Serve over ice.
