A hill top on which stood and will stand the Temple with 10 open miracles occurring every day for all to behold. The connection between Heaven and earth was revealed in Jerusalem. It's root shares the same letters as the root of chibehr because even in the destruction a connection was maintained. Only what is revealed. It is the hidden connection between Heaven and earth.
Destruction is for the senses.
A place that is hidden is not subject to destruction. The forefathers actually should have been buried on the Temple Mount but the churban then might have given the impression that the relationship between them and G-d was over. Therefore a special place had to be set up that was tantamount to the Temple Mount but indestructible. Now Rashi makes sense. Kiryat Arbah was named after 4 giants.