Line a baking sheet with parchment paper, set aside. Fill a bowl with ice and water and set aside. Cut lemons into very thin slices (use a sharp knife); remove and discard seeds.

Bring medium saucepan of water to a rolling boil over high heat.

Add lemon slices and stir gently until softened (to remove bitterness), 1 to 2 minutes. Remove from heat, drain water and place lemon slices in ice water. Drain lemon slices and set aside.

In a 10" skillet bring water and sugar to the boil over medium heat, stirring until sugar is dissolved and mixture is clear.

Reduce heat to medium-low and add lemon slices, arranging slices so they do not overlap. Simmer, uncovered, until lemon slices are translucent, about 1 hour.

Transfer to prepared baking sheet; allow slices to cool completely.