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 in Grand Theft Auto IV. It passes under the pedestrianised area of Castle Gardens and was presumably built to bypass the busy financial district, The Exchange.
||Union Drive West||n/b direction: Exit toward Union Drive West|
s/b direction: Entrance from Union Drive West
||Union Drive East||n/b direction: Entrance from Union Drive East|
s/b direction: Exit from Union Drive East