Named after the Exmoor ponies Marion Farnsworth and her partner, Helen Stanley Johnson, imported from England in the early 1920s, Exmoor Farm includes several buildings designed by Boston architect Eleanor Raymond. To accommodate Farnsworth and Johnson's growing family, which included five young female boarders and an adopted daughter, Raymond built an addition to the main farmhouse at 751 Boston Post Road. Known as the Big House, it was first moved from a roadside site to its current location. After the addition of five rear wings, the house contained communal living and dining spaces, private bedrooms for each of the six children, a master suite for Farnsworth and Johnson, a large playroom, and a shop for general carpentry and farm work.
In 1938, Raymond converted an old hen house on the farm into a two-story apartment for the farm's manager. The so-called Apple House Apartment features storm windows turned on their sides, a functional flat roof, and a bridge to reach the second floor from the adjacent higher ground. After the hurricane of 1938, Raymond used timber from fallen trees to build two identical rental Red Houses on nearby Gun Club Lane. The Red House at 56 Gun Club Lane remains virtually unaltered and reflects Raymond's interest in economical design, local materials, and the colonial vernacular.
One of Raymond's last commissions from Farnsworth was for the Colonial Revival house (1941) at 745 Boston Post Road. Built on the foundations of the relocated farmhouse, this house was influenced by an eighteenth-century house in Barnstable. Like the other Boston Post Road buildings, it is now privately owned and has not been significantly altered on the exterior.