The Alaska State Museum looks good and has unique looking gift shop. We are going to visit the St. Nicholas Russian Orthodox Church and probably even try one of the trolley tours. We also "thought" about the Glacier Gardens Rainforest tours. www.glaciergardens.com
they have a "golf cart" style train to take you through the garden. AND the Red Dog Saloon. Hope this helps
We, too, have booked the Yukon horseback riding. It sounds terrific. Our cruise is first week of August.
Enjoy your trip.