Castle Tunnel entrance
The Castle Tunnel is a two-lane tunnel that connects Union Drive East with Union Drive West via a tunnel under Castle Gardens at the southern tip of Algonquin. It passes under the pedestrianised area of Castle Gardens and was presumably built to bypass the busy financial district, The Exchange.
It is based on the Brooklyn-Battery Tunnel, although, it doesn't connect to Broker. It is based on the Battery Park portion of the FDR Drive in New York.