Come to Central Park of Naperville for this event! Market Place Opens at 5 PM The Naperville Sister Cities Foundation is a nonprofit committed to connecting Naperville and its citizens to the world. The Sister City Program was initiated on a global scale in 1956 as a creative force for international cooperation and goodwill through community action. Naperville’s participation in the program started in 1993 as the Naperville Sister Cities Commission, and the Naperville Sister Cities Foundation was formed in 1999. The foundation sponsors programs designed to foster inclusivity and diversity through cultural, education and business exchange between Naperville and its sister cities.