Preheat the oven to 80*C and remove the shelves.
Slice the oranges into 5-8mm slices. It looks thick but when they dry out they will go a lot thinner.
Once the pieces are sliced put them on kitchen paper and absorb as much juice as you can.
Place the orange slices on the oven shelf and pop in the oven for approximately 3 hours. But check the orange and turn them over each 45 minutes.
Allow them to cool and enjoy using them as decorations.