Wash the peaches and remove the pits. You can remove the skin, but I like leaving it on for this syrup. Dice the peaches.

Add the peaches, sugar and ½ cup of water to a saucepan and cook over medium until the peaches are soft and syrupy, and the sugar has all dissolved and is bubbling, about 7-8 minutes.

Remove the pan from the heat and very carefully transfer the mixture to a blender or a food processor. Place the lid on and cover with a clean kitchen towel before blending until smooth. You can strain out the solids if you would like by using a spoon or spatula to press the syrup through a fine mesh sieve. Cover the syrup and let it cool to room temperature or chill it in the refrigerator until you are ready to use it.

When you are ready to serve the lemonade, combine the peach syrup, lemon juice, 4 cups of cold water, and ice in a pitcher. Stir to combine. Add slices of lemons and peaches for garnish, if desired.