In a microwave safe bowl, heat the water and sugar in the microwave (or in a small sauce pan on the stove top) until the sugar dissolves into the water. Remove from heat.
Place the peeled and chopped mango into a blender. Cover and pulse a few times to break up the chunks. Then pour the sugar syrup, lime juice, and lime zest into the blender. Cover again and puree until just smooth. Don't over blend!
Pour the mixture into ramekins or small souffle cups. Freeze until hard, at least 2 hours.