In a medium saucepan, combine the water and sugar and bring to a boil. Stir the sugar until it has completely dissolved. Meanwhile, slice the lemons into thin slices. Once sugar has dissolved, add the sliced lemons to the sauce pan and stir to combine. Reduce heat to low and allow the lemons to simmer for 25-30 minutes. Remove from heat and allow the lemons to cool in the syrup. Carefully remove the lemons from the saucepan and place them on a wire rack to dry. Transfer to an airtight container and store in the the fridge until ready to serve.