I'd recommend jumping just one country over and exploring Armenia for even more of that history. It's astonishing how old the country is and how much of the ancient architecture is just sitting around. From churches carved out of mountains to old stones with religious symbols by the sides of roads and on mountains. The really cool thing to me about exploring it was how normal it was for everyone, much of those locations weren't bordered off and protected by guards.

I spent almost a month in Istanbul and saw some of the history, but I really had no idea how much more there was just sitting in the next nation over.