First of all, I don't mean the other people answers are not correct. But They have described a "very positive" side of Iran. So, I won't dare to call those answers useless and will try my best to give you a realistic view of my country. Because you are going to make a very important decision.
As someone who has lived in Europe for years, it's like going from heaven to hell. In many various aspects like freedom, economics, politics, culture etc. Iran is only suitable for those who want to travel as a tourist.
Covering head and body is called Hijab. If you don't observe Hijab, the police (or the moral police) will arrest you. There is no guaranty that they treat you well. So, yes, I would say it is dangerous (especially for single women).
But Hijab is not the only problem. You are not allowed to have dance parties, going out with your boyfriend (or any other man who is not a relative), selling or drinking alcoholic drinks in public places, there is no bar, no nightclub, the press is very limited, Internet connection speed is very low (128 kbps for home-users, plus there have blocked too many websites such as FACEBOOK, TWITTER, YOUTUBE and so many others), TV programs are worthless and you "soon" will need a satellite dish which is forbidden (but you still can get one illegaly, although they will cause radio jamming in order to censor news channels and pornography). Oh and "DOGs" are forbidden, too!.
There are restriction, discrimination (Shia Muslims only accepted. Although there is other followers while they treat them with injustice), moral collapse, homophobia and so on. It is pretty much look like Europe in Middle Ages! I mean "religious extremism" and other stupid stuff you can see almost everywhere that you will sick of it!
Iran is well known for supporting terrorist actions and has no reasonable face in U.N. Each year they impose more sanctions against Iran. Because of these sanctions, many western businesses companies (like APPLE) have no official dealers in Iran. Even very popular services like iTUNES or GOOGLE.
Politicians compare Iran's circumstance to North Korea! And you can realize the depth of disaster when the judiciary chief of Iran says: "We don't believe in Human Rights". (Sadegh Larijani)
You might think this is not concern you but the unemployment's rate is sharply rising. This factor shows that a country's economy going well or not. The more unemployment means more poverty and caused insecurity. Also the judicial system is completely corrupt.
The law of Iran is based on Islam, and Islam ignores women's right.
Iran is not even a good place for a Shia Muslim. because of religious extremism and regime's double standard behaviors. Also "Most of" people are religious (Shia). But big cities like Tehran, Shiraz, Esfahan are not "that" religious.
And finally good news! No country in the world is perfectly safe, but we don't have THAT much of rape in Iran. Because of religious beliefs? No, I would say because of the barbaric punishment: Execution.
My final words:
Iran is a country with no future and is very close to experience a regression. You will survive if you are that kind of person who is able to ignore her absolute rights, is able to stand too many pressure, have no other choice but to live in Iran, and will payed in Dollars!
If you had any other questions, please feel free to contact me.
An Iranian who live in Iran.