Two adults and two children (ages 6-12) can board the historic World War II Liberty ship S.S. Jeremiah O'Brien, Located at Pier 45 in Fisherman's Wharf, San Francisco.  The O'Brien is open for tours daily between 9am and 4pm except major holidays.

The SS Jeremiah O'Brien is one of two remaining fully functional Liberty ships of the 2,710 built and launched during World War II. The O'Brien has the distinction of being the last unaltered Liberty ship and remains historically accurate. Moored at Pier 45, Fisherman's Wharf, she is a premier San Francisco attraction.

A living museum on the National Register of Historic Places and a National Historic Landmark, the O'Brien transports you back almost seven decades to when sailors braved the harshest of high seas and threat of enemy attack.

http://www.ssjeremiahobrien.org