In a small saucepan, combine 1 cup of water and 1 cup of granulated sugar over medium-low heat.

Stir gently until the sugar is fully dissolved, which should take about 2–3 minutes.

Remove from heat and let the syrup cool slightly before pouring it into a large pitcher.

While the syrup is cooling, juice 8 fresh lemons until you have about 1½ cups of lemon juice. Strain out the seeds.

Add the lemon juice to the pitcher and stir it with the syrup.

Pour in the remaining 7 cups of cold water and stir well.

Transfer the pitcher to the fridge and chill until cold.

Just before serving, add ice cubes and a few lemon slices for presentation.