I'd like to see the Twain home someday, I'm a fan and my father was a huge fan of his.
Some places you can go if you want to vist the historic places of Mark Twain:
Hannibal, Missouri - Childhood home
Virginia City, Nevada - Where he was a journalist.
Mississipi River - Where he was steamboat pilot
Elmira, New York - His Summer home and burial place
Hartford, Conneticut - His later home
Hannibal Missouri childhood home. The house is still there.