You can really make a day of it in Duluth, Minnesota.  We spent a little time in the Great Lakes Aquarium, then walked around the water front for a bit and even took at boat tour of the harbor.  The first set of photos above is of the Great Lakes Aquarium and the view of the harbor from there.  You could spend a couple of hours just watching the harbor traffic.

The photos above are part of the display of ships, I am assuming, that belong to the Maritime Museum.

As I mentioned before, we took a boat tour of the harbor.  The first leg was a short trip under the bridge and outside the harbor.  The tour afforded us a great view of Duluth's skyline.  One thing I want to point out in the first photo is the height of the ship as compared to the four story building just to the left of it.

The rest of the boat tour was spent inside the harbor, and even though it took an hour, we only covered a small portion of the area.  A couple things to point out: In the first photo are four tugboats that are still used to move the larger ships.  However, they are a bit expensive to use if you have to.  The tugboats are named after states.  From right to left are the North Carolina, North Dakota, Kentucky, and I believe that the last one is the Minnesota, but it's very hard to make out.  In the next two photos, you can see parts of wind turbines waiting on the docks.  These actually came from Sweden, if I remember correctly.

We came across the lake boat below, the first picture, as it was turning one hundred and eighty degrees in the harbor, after pulling away from the loading dock.  Then, as we were heading back, we caught up to it and passed by very close.  I found out, while doing a little research on the Roger Blough, that the two ships had actually had a minor collision.

Here are a couple of other lake boats being loaded down with iron ore.  Some ships have self-unloaders, the booms swung out to the sides.  They need to swing them out when loading.  If you look closely in the last picture of the series, you can actually see a basketball hoop on the foredeck of the lake ship.

Another interesting place to visit is the Rose Garden.  This actually covers a portion of the main highway heading up the North Shore.  I really like how they designed the highway underpass in the Viking theme.  Speaking of Vikings, the last picture is of a replica Viking ship that was built in Norway, then sailed across the Atlantic Ocean, through the Great Lakes, and finally stopping at Duluth.  From what I understand there is an organization trying to raise funds to construct a building around it.  Right now, they only uncovered it during certain times of the week.  Unfortunately when we were there, it was covered up.