Two good museums. Especially the Heinz. If you are looking for other options, head toward the Natural History Museum, not far from the Pitt campus. Near there, a few blocks away is the left field wall from Forbes Field. I believe Home plate is inside the Law School.
I would also recommend Point State Park. The museum there is interesting. This was the site of the fort during the French and Indian war. Some nice views of the football stadium there as well