Wash the limes thoroughly and cut each into approximately 8 pieces, including the skin.

In a blender, combine lime pieces with cold water and sweetened condensed milk. Blend on high for 30-60 seconds until smooth.

Strain the mixture through a fine mesh strainer or cheesecloth into a large pitcher, pressing to extract liquid.

Add ice to the pitcher or refrigerate for about 30 minutes. Serve over ice-filled glasses.

Store leftovers in the refrigerator or pour into popsicle molds and freeze.