If you just show some modesty, and do not wear very suggestive clothes, wear a scarf to cover the top of your head and not wear too much make make up, you should be fine. Iranian women who cover their whole body with " chaadoer" do it by choice.
Make sure to visit Persepolis, and walk up the steps to the palace area. The steps were built short so that people could go up the steps with horses.
Suggest you do some research and check with Iranian consulate...They can give you some basics on dress and behaviour... Truthfully, have no idea why you would want to vacation there, unless you have family living in Iran... Men from that country, treat women worse than dog dung or farm animals... Hope you have lots of money, so you can live in a protected area.... If you truly want to have a vacation there.... PLEASE be cautious...
Go onto the home office website - it will tell you what you can or can't do. Interesting choice of holiday!!
do you have to cover your body like the women there do?
I don't know! but these can help you a lot:
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>>>'Men from that country, treat women worse than dog dung or farm animals'
it is NOT true