Muddle 2 lime wedges and some mint leaves in each glass and add ice. Mix 2 cups simple syrup, 2 cups water, 1 1/2 cups fresh lime juice and 1/2 cup fresh lemon juice in a pitcher; pour into the glasses.
Simple Syrup: To make 2 cups simple syrup, bring 1 1/2cups each sugar and water to a boil, stirring until dissolved. Let cool.
Photograph by Jonathan Kantor