Looking around on the net and I found that Alcatraz is pretty accessible!
Pier 33 Alcatraz Landing and all Alcatraz Cruises boats are fully accessible, in addition to many areas on Alcatraz Island with the use of the S.E.A.T. (Sustainable Easy Access Transport) Tram. Assisted listening devices, audio described opportunities, tactile models, large font type and Braille audio tour scripts enable everyone to enjoy the rich history and stories exhibited throughout Alcatraz Landing and on Alcatraz Island.
The website has a bunch more information, but the only real issue may be steep inclines – though there is an accessible tram available called S.E.A.T. (Sustainable Easy Access Transport) Tram.