Combine the sugar and water over medium heat in a saucepan until syrupy, stirring occasionally to prevent burning. Thinly slice citrus, cutting in half from the stem first and then each half into crescents. Cook these pieces in the hot sugar solution over medium heat for about 10 minutes. Cover a baking sheet with parchment paper and transfer the sugared fruit to it. Bake at 235°F for 20-30 minutes until the fruit is shiny and the texture crisp. Allow the fruit to cool before removing from baking sheet. Larger fruit takes longer to bake.