What to see in Turkey?

[Dan Diffendale]

It looks increasingly likely that I will be teaching English in Turkey for a year or two come September, so I'm looking for suggestions as to what to see. I'll be there for quite a while, obviously, but will be somewhat limited by class scheduling in terms of how much time I have. Not sure yet whether I'll be in Istanbul or Ankara, but anything in Turkey is fair game for suggestions. Doesn't have to be limited to Roman stuff, though that's welcome. And I'll certainly photograph any tombstones I come across...