Tunnels are generally my nemesis (I hate being underground). The only one nearby that I would possible have to deal with, the Whittier Tunnel, is closed to bicycles. It is the only thing keeping me from being able to access the Alaska Marine Highway System by bike within a day's ride, without having to arrange a lift from someone.

An intersting side note for you. Due to how the town was established, and subsequent land and terrain issues, almost every resident in Whittier, Alaska lives in the same building.