Here is 221B Baker Street, and the site of the Sherlock Holmes Museum and Obligatory Gift Shop.
Well, sort of.
It's suspiciously between 238 Baker Street and 240 Baker
Street. It would seem that the SH Museum had to settle
for the closest address to 221B available, seeing as the REAL 221B
Baker Street doesn't exist. If you follow street numbers to try to
find 221, you will find a bank, the same bank that was there
back in the 1800s, if I remember right. But there is a plaque
on the outer wall of the bank marking the spot where 221B Baker Street ought to