Wash peaches and chop them into chunks (remove pits).

In a saucepan, combine chopped peaches, sugar, and 1 cup of water. Bring to a boil over medium-high heat.

Reduce heat and simmer for 10-15 minutes, mashing peaches slightly, until sugar dissolves and liquid thickens.

Strain the syrup through a fine-mesh sieve into a bowl, pressing on the fruit to extract all flavor. Let syrup cool completely.

In a large pitcher, combine the cooled peach syrup, fresh lemon juice, and 4 cups of cold water. Stir well.

Taste and add more water if too sweet, or more sugar if too tart.

Serve over plenty of ice, garnished with fresh peach slices and lemon wheels.