Remove 2 tablespoons zest from lemons. In a small saucepan, stir together 2 cups sugar, 1 cup water and the lemon zest. Bring to a boil over medium heat; reduce heat. Simmer, uncovered, until sugar is dissolved. Remove from heat and let cool to room temperature. Cover and chill lemon syrup 24 hours. Strain through a fine-mesh sieve; discard zest.