The Old Town Mill was originally built in 1650 by John Winthrop Jr., the founder of New London and later the Governor of Connecticut. Listed on the National Historic Register, the Mill is one of the oldest industrial sites in Connecticut. On September 6, 1781, General Benedict Arnold burned the mill down during his raid on New London. The mill was rebuilt soon after on the original site.

The grounds of the Old Town Mill are open year-round until sunset. The mill is also available to groups by special appointment.