Place the chunks of watermelon into a blender bowl or bowl for hand blender and add the lime juice if using.
Blitz until smooth.
Pour the mixture evenly into ice lolly moulds, leaving ½cm (¼ ") at the top to allow room for the lollies to expand during freezing, and freeze overnight or until firm.
To serve, dip moulds briefly in hot water to loosen and carefully remove the watermelon lollies.
Notes
Hand blender v blender: both work just as well. I have found when using the hand blender the ice lollies/popsicles freeze in one colour, when using a high speed blender they seperate slightly like in the photos in this post. They taste just as good, but look really pretty too! It's totally up to you which you prefer.Watermelon: choose one that is heavy, it should be sweet and flavourful.Leave enough room at the top of the lolly molds to allow room for the ice lollies to expand during freezeing - around ½ cm (¼ ")