Who even invented this wall? one could call it a conspiracy. 200 years ago they took a place and decided it is holy to Jews. Why? Where is it ever mentioned? Have you ever read about it in the writings of Chazal? By the Rishonim? by the Achronim? Professor Yeshaya Lebovitz decided it is a "disco-wall" and I agree with him. It is nothing... to go to har Habayit one must immerse in a mikva and take off his shoes. This is a holy place. What rules are there for going to the Kotel?

  -- Yehuda Glick, about the Kotel, during an interview about Har Habayit

despite my following his point from an historical and technical point of view, I do think the Kotel has at least the holiness of a beit knesset. it has been used for tens or hundreds of years, as a gathering place for Jews to pour out their hearts and to meet in prayer. It must have some holiness just because of that. Granted, that is not anything near the holiness of Temple Mount, but it must have some level of holiness