Khaju Bridge, Isfahan
Here's another historical site to visit if you come to Iran: Khaju Bridge in Isfahan, which was built around in the year 1650. Like Shiraz, Isfahan has many places worth seeing. For more info on Isfahan, you might want to take a look at Wikipedia. Although it's not always accurate with regard to Iran's modern history, it can give you an idea of the more ancient history, at least with regard to architecture.