Bring water to a boil and add mint leaves. Lower heat until mixture is simmering and cook for about 30-40 minutes until liquid is reduced. Add sugar and stir until dissolved. Remove from heat.
Add watermelon to a blender and puree until smooth. Pour into a strainer lined with cheesecloth to remove pulp.
Add watermelon juice and lemon juice to a large pitcher and add a pinch of salt. Stir in mint simple syrup.
Keep in refrigerator until ready to serve. Stir before pouring into glasses with ice. Enjoy!
Recipe by For the Love of Gourmet at https://fortheloveofgourmet.com/watermelon-mint-lemonade/