Place chopped watermelon in a blender jar and purée. If you wish you can sieve it. Set aside.
In a jar or a glass, muddle together mint leaves, lemon slices and sugar.
Divide the mix into four tall glasses, add watermelon puree, lemon juice and ice cubes.
Add lemon slices and gently pour the club soda.
Give a stir and garnish with mint, watermelon wedges and lemon slices.
Serve immediately and enjoy! Mojito can be made with other fruits like Lemon, Strawberry, Passion Fruit.