Preheat your oven to 170 degrees Fahrenheit (80 degrees Celsius).
Thoroughly clean limes using fresh water.
Use a sharp knife or mandolin to slice the limes along the hemisphere, so that you have wheels of lime that are about 1/8 of an inch thick.
Place the oven rack into your oven tray. Then arrange the limes in a single layer on the oven rack. Make sure there is plenty of space between the limes for the air to circulate.
Bake in the oven for 3-5 hours, turning every hour or so.
The limes are ready when all the moisture has evaporated and they feel light, dry and brittle. Store in an airtight container in the pantry.