Combine water and sugar in a medium to large saucepan.
Bring the mixture to a boil for 1 minute or until the sugar has dissolved, swirling pan occasionally.
Add lemon slices into sugar syrup and turn to coat each slice.
Turn down the heat so that the lemon slices are gently simmering and cook for approximately 45-60 minutes or until the rind of the lemons is translucent. The cooking time will depend on how thick the lemon rind is on the lemons.
Preheat oven to 200 degrees Fahrenheit.
Using kitchen forceps or tongs gently lift lemon slices out of syrup, allowing excess to drip off, and place on a wire rack set over a sheet pan. Bake for 60 minutes, or until lemon slices become slightly firm. They will firm up more as they cool.
Allow lemon slices to cool and store in an airtight container in a cool dark place for up to 1 week or refrigerate up to one month.
Use to decorate cakes, cookies, cupcakes and garnish drinks.