01 - In a small saucepan, combine the sugar and ½ cup of water. Heat over medium heat, stirring constantly, until the sugar has fully dissolved. Remove from heat and set aside to cool completely.
02 - Add the sliced peaches, freshly squeezed lemon juice, and lemon zest to a blender. Purée on high until completely smooth and no chunks remain.
03 - Pour the peach purée through a fine-mesh sieve into a large pitcher, pressing with a spatula to extract as much liquid as possible. Discard the pulp or reserve for another use.
04 - Add the cooled simple syrup and 3 cups of cold water to the pitcher. Stir thoroughly until well combined.
05 - Taste the lemonade and adjust sweetness or tartness by adding more sugar or lemon juice as desired.
06 - Refrigerate for at least 1 hour before serving, or pour immediately over ice-filled glasses. Garnish each glass with fresh mint leaves, peach slices, and lemon wheels.