Wash 6 fresh limes thoroughly to remove any dirt or wax. Cut each lime into about 8 pieces.

In a powerful blender, combine chopped lime pieces, 3 cups of cold water, and 1 cup of sweetened condensed milk. Blend on high for about 30 seconds until smooth.

Using a mesh strainer placed over a bowl or pitcher, pour the blended mixture to remove pulp and peels. Use a spatula to extract as much liquid as possible.

Fill two tall glasses with ice cubes and pour the strained limeade over the ice. Garnish with a lime slice or a sprig of mint. Serve immediately.