The idea of ranking holy sites on some kind of Billboard chart is kind of silly. What are the holiest sites in Christianity? Calvary? The Church of the Sepulcher? The Vatican? The Church of the Nativity? The Mormon Tabernacle? Canterbury? Constantinople (now it's Istanbul, not Constantinople)?
Even if you can compile a list most Christians would agree upon, try listing them in order and watch the consensus disappear.
the holiest site in Christianity is the soul. The idea that objects places or things are to be worshiped and ranked should be considered blasphemous by any modern worshiper!
Mohammedans place far greater improtance to locations and buildings than protestants do.
That being said, Mohammedans have destroyed all sorts of non Mohammedan shrines and buildings over the centuries.