Fort Heath was a United States military installation located on the coast of Winthrop. It served as a coastal defense site and a radar station for air defense. The fort was decommissioned in 1974 and transferred to the Federal Aviation Administration, which operates a radar facility on the site. The fort's history dates back to the colonial era when it was used as a lookout point and a signal station. During the World Wars, it was equipped with guns and searchlights to protect the Boston Harbor. In the Cold War, it became part of the Semi-Automatic Ground Environment (SAGE) system, which monitored and controlled the airspace over the northeastern United States.