Chris you will have no problem. I am English and have been to Iran twice. Tehran is surrounded by beautiful scenery (mountains and lakes) although it can get really cold.
Just dress appropriately - the Iranians are very welcoming people, and love to show people around their beautiful country. Plus it is not as fundamentalist as people think (the population is young, and change is in the air).
I used to think the brain is the most fascinating part of my body. But, hey, who is telling me that?