Urban sociologist Ray Oldenburg defines a third place as a place of refuge other than the home or workplace where people can regularly visit and commune with friends, neighbors, coworkers, and even strangers. Because little is known about the place-based physical qualities of third places that support sociability and place attachment, this article examines how four urban design characteristics distinguish third-place businesses from other businesses on the Main Street. The article discusses a study conducted at Main Streets in two cities and one town in Massachusetts. As part of the study, visual surveys measured urban design qualities of businesses on the Main Streets, and interviews helped determine user perceptions. The findings suggest that third places are relatively high in both personalization (distinctiveness, recognizability) and permeability to the street, but seating and shelter provisions are perhaps the most crucial urban design characteristics that contribute to sociability on the Main Street.