when i travel to shiraz, iran, I visited ShahCheragh(Shrine of king of the light). when women enter it, we have to wear Chador, a cloth which covers women from head to feet, as for visiting other mosques, we just need a hijab like the other time. I am impressed a lot by this place not only because it need no entrance fee, unlike most other tourist spots in iran, but also there are a lot of free and hospitable guides introducing for us of it. It was a good experience in Iran :)