Start by dicing the watermelon into small cubes. You can remove the rind if you prefer, but it's not necessary.

In a large pot, combine the watermelon, sugar, and lime juice. Stir until the sugar is fully dissolved.

Bring the mixture to a boil over medium-high heat, then reduce the heat and let it simmer for about 30 minutes, or until the watermelon is translucent and the liquid has thickened to a syrupy consistency.

Use a slotted spoon to remove any foam that forms on the surface of the mixture.

Remove the pot from the heat and let the candy cool to room temperature.

Once cooled, transfer the candy to an airtight container and store in the refrigerator for up to 2 weeks.