In a medium-sized saucepot add fresh cranberries, sugar, and water.

Add to medium heat and let the mixture simmer for about 10 minutes. You do not want the mixture to boil or the cranberries to burst.

After all, the sugar is incorporated and the mixture takes on a pink hue, take it off the burner and let it cool to room temperature.

Once cranberry simple syrup is cool it's time to make the drink! You should have about 1 cup of simple syrup.

In a tall glass add mint leaves and lime juice.

Muddle slightly to release the mint flavor.

Fill glass with ice and add in 2 ounces cranberry simple syrup and 2 ounces rum.

Top with seltzer water and add some fresh cranberries for garnish.