Chatham covers an area of 24.33 square miles at the "elbow" of Cape Cod, Massachusetts and is bordered by Pleasant Bay and Orleans on the north, the Atlantic Ocean on the east, Nantucket Sound on the south, and Harwich on the west. The town, orginally known as Monomoit, is 17 miles east of Hyannis, 89 miles southeast of Boston, and 223 miles from New York City. The Chatham Town Hall Offices are located at 549 Main street, Chatham, MA 02633.