Where and What to See in Istanbul?

It is really a very hard question to answer. Since it is a huge city, there are many interesting places to see. It would take weeks to explore the whole city. I myself have not seen it completely, but I will try to explain the main points that you should not miss, and some small tips. At the end, I will be talking about the places you should avoid. Please click on the names of the places for further information.