Istanbul tips

Hello Istanbul,

I will be travelling to Istanbul from Sep 23rd to 27th and looking for any insider hints and tips that you can provide.
What shouldn't we miss seeing?
And your suggestions on your favourite restaurants, bars and clubs will be most appreciated!
If there is anything going on then, please keep me posted and would love to join in. Shame I will just miss the official InterNations event!

Thanks all
Deepika