Wash the watermelon well and slice it in half. Save half of the watermelon for regular snacking! For the other half, use a spoon or melon baller to scoop out all of the watermelon from the rind, transferring the watermelon fruit to a bowl. Scoop the rind clean, leaving the rind intact. You should have half of a rind that will act as a bowl!

Add all of the watermelon a food processor or blender. Blend on high until liquid. Add the berries and lemon juice and blend again until liquid.

Set a fine mesh strainer over a medium/large pot and slowly pour the liquid over the strainer, stirring the strain out any seeds or solid pulp. Save the pulp to add to a smoothie if desired! Sprinkle the gelatin over the juice mixture and lightly mix. Allow to harden for 2 minutes.

Transfer the pot to the stove and heat over low heat for 3-4 minutes or until fully liquid.

Place the halved watermelon rind inside a bowl to keep it stable. Carefully pour the liquid into the rind and transfer to the fridge. Allow to set over 5-6 hours, or overnight to fully harden.

Once hardened, remove from the fridge and place on a cutting board. Slice the watermelon rind into pieces for snacking and serve chilled! Enjoy the jello and discard the rind.