Is there a limit to the physical size of a layer 2 broadcast domain?

I feel like this needs to go into a weekly no stupid questions thread, but not sure you guys do that here.

Let's say you had two locations that are reasonably far apart and you wanted to connect via ethernet and all you had was a bunch of unmanaged switches. Assuming you could physically run ethernet from point A to point B and could put a switch every 100 meters, is there a limit as to how far you could go?