Naperville, city in northeastern Illinois, in both DuPage and Will counties. The city is located on the western branch of the DuPage River and is part of the Chicago metropolitan area. Naperville is a residential and commercial city and a center for industrial research. Manufactures include specialty chemicals. Near the city are Argonne National Laboratory and Fermi National Accelerator Laboratory, both of which are major institutions focused on advanced research in physics. Educational institutions in Naperville include North Central College (1861) and a junior college.
Also in the city is Naper Settlement, a recreated village of the early 1800s. The city's Historic Preservation District includes more than 150 examples of 19th-century architecture. Other area attractions are the Morton Arboretum and SciTech, an interactive science center. Joe Naper Day, honoring the city's founder, is an annual event.
