Taft Tunnel in Lisbon, Connecticut is the oldest tunnel still in railroad use in its original form as part of the current Providence and Worcester Railroad. It was originally built by the Norwich and Worcester Railroad in 1837. It is a tunnel through hard rock and is approximately 300 feet long. It allowed the Norwich and Worcester to generally follow the Quinebaug river between Norwich and Clayville Connecticut.
The Taft Tunnel is second oldest to the tunnel originally constructed by the New York and Harlem Railroad at Yorkville, Manhattan in 1837, whose right of way is still in heavy use by the central tracks of the Park Avenue Tunnel. The Taft Tunnel is the oldest tunnel that is still used today.
Coordinates: 41°33′16″N 72°02′10″W / 41.554437°N 72.036227°W