My first advice would be to ignore the post above mine, because it has nothing much to do with reality in Iran. The majority of Iranians are religiously indifferent, they welcome the foreigners even Americans and, of course, everyone is free to visit even the most isolated Zoroastrian shrine. You're only prohibited from visiting some mosques, but these are not related to what you're interested (ancient history). That's why I'll leave the medieval monuments and cities (like Isfahan and Bam) aside. First and foremost, you must visit Persepolis. In my opinion, it is the most magnificent archaeological site, which is to be expected, considering it is the ceremonial capital of first huge empire of history, that fortunately for the lovers of history, was not inhibited since her destruction from Alexander: Your next destination should be Naqsh-e Rostam, again a magnificent archaeological site located near Persepolis, where you could see the tombs of several Achaemenid kings, as well as the famous rock reliefs of the Sassanid era, depicting the humiliation of Valerian by Ardashir. Then, we have Pasargadae, the first Persian capital, whose landmark is the Tomb of Cyrus II, the man who established the Achaemenid Empire. Also located close to Persepolis, since SW Iran was the ancient province of Persis, from where the Sassanids and the Achaemenids emerged. Basically, these the most famous and impressive ancient landmarks of Iran, but if you feel adventurous, I'd also suggest Susa, the capital of Elam and the Achaemenids, which has been excavated, but it's not as amazing as Persepolis. However, not many archaeological sites are comparable with Persepolis, are they? Finally, something a bit different. Iran is also famous for its qanat system, a brilliant way to redistribute water where it was needed. Qanat tunnels, dating back to pre-Achaemenid times could be visited in many modern cities, like Isfahan or Tehran, but if I were you, I would also pay a visit to the Kish island. Unfortunately, it gradually turns into a glamorous Las Vegas, the Dubai of Iran, but still not many know about its underground town: P.S. When I google Persepolis, all the results concern that mediocre film of Satrapi. Jesus, why people find the sexual frustrations of a rebel teen more enjoyable than the Persian ruins is beyond me.