"The Belzer Rebbe, Rebbe Ahazon, zatsal, when visiting the wall would search for a certain protruding stone. He would pray at that spot, explaining that his father, Reb Yissachar Dov, zatzal, had told him that this stone was directly opposite the Kodesh Hakodashim (Holy of Holies)." (page 7: http://ohr.edu/ohrnet/5759/bereishi/noach.pdf)
Which stone is it ? Do you have a picture of it or way to find it ?
There is no stone on the exposed kotel which is opposite the kodesh hakadoshim. However if you go to the tunnel tours there is a spot marked which is.
See this page for maps and pictures:
http://www.generationword.com/jerusalem101/38-western-wall-tunnels.html
The Belzer Rebbe, Rebbe Ahazon moved to Israel in 1944 but passed in 1957. The western wall was off limits to Jews from 1948 until 1967.
Here is a picture from the side of what the Kotel would have looked like to anyone visiting the Kotel between 1944 and 1948.
I have looked at other images as well, and the only stone that appears to be protruding to me, is the one which is next to the large bush, about 7 stones up, and about 13-15 stones away from "close edge". In the 1920s, the British "cleaned up" the wall, for the sake of it being a world heritage site, or something similar.
Other pictures from the era, do not show any stones sticking out, but one stone in particular is seen as being pushed in. That stone can be seen even today, and it is easy to spot.
