Did Sir Arthur Conan Doyle make up the address 221b purely for Sherlock or was it real?

Sir Arthur Conan Doyle did not invent the address 221B Baker Street. It existed, but not quite in the way Doyle described it.

Here's the breakdown:

* The real Baker Street: The address itself was real, but in Doyle's time, the buildings on Baker Street were numbered consecutively. There was no 221, and 221B didn't exist.

* Doyle's fictionalization: Doyle simply chose the number 221B for his fictional creation. He likely did this for two reasons:

* Symbolism: The "B" could symbolize the "Baker" part of the street, adding a touch of whimsy.

* Uniqueness: It was an unconventional way to address a building at the time, giving Sherlock's residence a distinctive touch.

* Modern reality: The building that now houses the Sherlock Holmes Museum is located at 221B Baker Street. However, this is a modern addition. The original building at that address was demolished in the 1930s. The current building was constructed in 1990 and designed to resemble the one described in the books.

So, while 221B Baker Street was a real address, it wasn't the actual residence of Sherlock Holmes. It was a fictional creation by Conan Doyle, and the current 221B Baker Street building is a homage to his famous creation.