Tremont Street Subway - Park Street station (first U.S. subway tunnel)

The Tremont Street Subway, which opened in 1897, is widely recognized as the first subway tunnel in the United States and is now part of the MBTA Green Line. Park Street station was one of the original stations on that subway and is located beneath Park Street Church at the listed address. The tunnel originally carried streetcar traffic and was later integrated into Boston's modern light-rail network; Park Street station remains an active transit hub.