Every year, 10 historic properties along Great Road, one of the oldest highways in the country, invite visitors to an Open House to get a peek inside these rare sites, ranging from 17th, 18th, and 19th centuries. Take a self-guided tour of the sites at the Great Road Heritage Campus: Hearthside House, Pullen’s Corner Schoolhouse, Hannaway Blacksmith Shop and the Moffett Mill.  The other participating sites include the Friends Quaker Meetinghouse, the Arnold House, Mt. Moriah Lodge, Northgate and the Arnold’s Bakery. The Valentine Whitman House, private residence, offers an outdoor visit to learn its history.  Free event.