The million dollar question is, do we know with positive certainty where the mokom azara is? Did you know that there are over a dozen opinions of Rabbis and archeologists on the subject!?
According to the רדב"ז the dome of the rock is the location of Kodesh Hakodoshim. However there has been much debate and many are of the opininon that it is where the trees are in front of the kosel. The zohar states that the place of Kodesh Hakodoshim will never be built on. This would result in everything shifting south, throwing a huge wrench into the reasoning of thoe who go on to har habayis.
Additonally, even according to the Rambam; it is prohibited to go past the chail if you have tum'as meis even if just miderabanan. The Rambam understands that the chail is a wall 10 Amos tall who's width is unknown. Unlike other Rishonim who understand that it is an area 10 Amos wide. This will result in an huge swath of unknown on the Har Habyis.