Visit Kenwood Estate at Hampstead Heath, London, England. It was the home of Dido Elizabeth Belle, a mixed-race child adopted and raised by an aristocratic family at the height of the slavery debate in England. Today Kenwood House is an art museum free to the public, and the grounds provide community park space. My favorite room was, of course, the library.
The Sherlock Homes Museum at 221B Baker Street, London, England is a must visit for any Sherlock fan. Enter the boarding house of Sherlock and Watson.