Little Women question - what is the Row (some kind of destination)?

In the book, Little Women, there is this conversation:

From here.

Now, I never knew what it was, either, but I have never traveled Europe so I figured I was just a hick like Amy. Upon speaking to someone who has traveled Europe far more extensively than I have, however, it transpired they didn’t know either.

So? Does anyone know what it is?

Probably a reference to Rotten Row. Yes, I have read way too many Regency romances!

That’s always been what I thought. It makes me think there must be a reference to Rotton Row after Amy goes abroad.

There is - in the letter she writes about being in London (Part 2, Chapter 31).

Oh, thank you! I admit to skimming a lot of the letters, though I loved the novel - they got long and boring, and the last thing I want to do is read a young girl’s treatise on the world. But thanks - I have always wondered.