If the Fenton family had been Mexican and settled in Hayward instead of Oakland, they would have opened United Paleteria Y Neveria. United's ice cream shop is hidden in plain sight in an unassuming strip mall fronting the six-lane Mission Boulevard just south of downtown Hayward. For out-of-towners, it can be easy to miss, which is too bad, because United makes some of the best sweet-citrusy-spicy mangonadas in the East Bay. The shop has ice cream, nieve, as well as frozen fruit bars, paletas, in addition to other old timey and neo-Mexican desserts. United's selection of ice cream flavors spans everything from the classics, such as pistachio and chocolate, to gummy and chunky flavors that will clog your teeth with candy and dough. Hayward's municipal pool is right across the street, and United is a destination for families on the weekends, so it can get crowded. But it's worth making the trip.