Most obviously, you missed the Most Great Prison itself, with the part that Baha'u'llah occupied.
Also, you missed the Ridvan garden.
Please note that by it is a house that Baha'u'llah and 'Abdu'l-Baha occasionally occupied briefly.
And at Mazra'ih, note that there used to be an aqueduct running right by the back of the house; you can still see the channel where it passed by.
At the World Center, the monument gardens are down near the center of the Arc.
The house in front of Ruhiyyih Khanum's grave used to be the western pilgrim house.
There's a large oval walkway around Bahji. Just outside its northwestern quadrant (the same quarter as the Shrine of Baha'u'llah) is a large tree (there used to be two, but one died several years ago) where Baha'u'llah used to go to picnic. My wife and I had our lunches there while we were visiting. Don't forget about the souvenir rubber stamp in the visitor center at Bahji that you can put into prayer books and other books while you're there.
Don't forget to read the last few pages of Epistle to the Son of the Wolf about the benefits of special activities while in Akka!
Enjoy your pilgrimage!