I think this is a great essay. It has a natural flow to it and you have presented plenty of good facts. :)
Here are a few suggestions you might find useful.
There is no denying that for a magnificent building, the appearance is vital.
Appearance is the vital element for a magnificent building.This architecture is the landmark or a symbol of city and represents the specific cultural ethos, which in turn attracts the tourists from all over the world and raises the sense of national pride for residents.
... This is an very important sentence. But i got the feeling that it was a little too long. Try to break it down to 2.
More importance should be attached to better the internal function and safety condition.
More importance should be given to the internal function and the safety aspect of the building.your essay is very good. I hope my suggestions were of use. :)