USS Becuna
You can tour this 307-foot-long Balao-class submarine (with a \"guppy\" conversion), that was launched in 1944 and conducted search-and-destroy missions in the South Pacific. A free audio tour, available with the price of admission, tells amazing stories of what life was like for a crew of 80 men, at sea for months at a time, in these claustrophobic quarters. Then you can step through the narrow walkways, climb the ladders, and glimpse the torpedoes in their firing chambers. Tickets are available at the Independence Seaport Museum.