It was our first trip to Iran, and I can say it was one of the most interesting place I've ever been in my life. When you staying in Tehran please make sure that your guide is Ahmad or Ghazal. We spend 2 amazing days (I know it's not enough) in Tehran with them. Ahmad and Ghazal are very professional, kind, knowledgeable, open minded and just a good people. Even I'm not a native English speaker it was very easy to understand them (wonderful translation skills). We deeply impressed by people, history and culture. I highly recommended you to visit Iran, one of the most hospitable, enjoyable, historic and safe destination.