Port Jackson, more commonly known as Sydney Harbor, known to be the largest natural harbor in the world is one of my favorites to enter by cruise ship and to wonder the various areas. When entering the harbor the views of the iconic and world famous Sydney Opera House and the Sydney Harbor Bridge, nicknamed the "Coathanger" because of its arch construction, are totally striking.
There are all kinds of tour offerings of the harbor area, but none of views are as striking from the 16th floor of a large cruise ship.
If you're from the United States and want to see Australia, one of the best ways to do it if you have the time is aboard a cruise ship, and if you do that, I would suggest selecting one of the repositioning ships as they generally have a bang up party like entrance into the harbor for publicity purposes. You can view the ship I was aboard when entering the harbor at: https://www.youtube.com/watch?v=gaHzRK-IRk8
Oddly you may hear of the World War II "Battle of Port Jackson." They seem to make a big deal of it, but if you bother to research it, it didn't amount to much. It seems three Japanese mini-subs attempted to enter the harbor. One got caught up in a submarine net whereupon the crew detonated the sub, killing themselves in the process. Another grounded in Taylor Bay, whereupon again the crew of two committed suicide rather than chance captured and the third fired two torpedoes at the USS Chicago, both of which missed. So there were only two torpedoes fired, nothing hit, no real damage and the only casualties seem to have been Japanese suicides. read more