Bring sugar and water to a boil in a medium saucepan.
Add two rosemary sprigs, lower heat, and let simmer for about 10 minutes, until syrup thickens.
Remove syrup to a jar or bowl and let cool.
Fill a cocktail shaker with ice, along with 6 ounces pomegranate juice, 3 ounces gin, and 1 ounce simple syrup (If you like a stronger cocktail, feel free to add a little more gin).
Shake it up and then divide into two glasses filled with ice.
Top with soda water, a sprig of rosemary, and pomegranate arils for garnish.
Optional: Place pomegranate arils in the bottom of an ice cube tray, fill with water, and freeze. Use ice cubes in cocktail glasses.