teheran visit (Tehran)

ciao!
i am passing by teheran for twodays and 15 days route thru west Iran. I am eally happy finally to visit thisn country, i am very curious about I ead a lot, but also feel T. is so big, and time so little and of course, I dont understand parsi ;-)
so i probably take a guide (we are 6 people)..for one day and then ..the second we manage ourself. above all i was wonder where and what to do for an easy and nice evening time. we will be probably tired from flight (4 am)...the we go down to isfan, shiraz with several stops...
any idea? maybe interantion event?

days will be 27/28 december
ciaoooo
Simone