in a small pan over medium heat, bring the water and sugar to a simmer. Cook, stirring occasionally, until the sugar is dissolved, about three minutes. Remove from the heat.
Place the ice cubes in a large bowl. Add the sugar syrup and stir until the ice is melted. Stir in the lemon zest and juice. Refrigerate until chilled, about one hour.
Freeze the mixture in an ice cream maker following the manufacturer's directions. Or freeze it in a pan, then break into chunks and puree it in a food processor.
Serve at once or scrape the lemon ice into a plastic container, cover, and store in the freezer for up to 24 hours. If it gets too hard, let softened briefly at room temperature. Serves 10 to