I started by searching for a pub. Then I saved that location ("save to my maps") and did another search and so on until I had saved all of the pubs I was interested in to a map of their own. I then clicked on that map name in the side-bar and found that there's a drawing tool, so I was able to draw a line connecting the pubs.
The final result is saved in a map that's publicly viewable as "Cambr
It seems as if, every day, I find new reasons to be impressed with Google's services.