I have heard of that happening, but I was also told theat neither side allowed it for long periods of time. The reason why I doubted it at first was that every time I read about this, they never mentioned where it was, so I assumed (after a while) that it was an urban myth of sorts.
At 60 feet apart, chances are that one side or the other would have withdrawn to a more defensible position after a very short period of time. It does make an intersteing historical site, though.
Dean.