entry Information needed (Tehran)

Hello Tehran!

Could You please help me with Your experience:

Is it possible for me as Austrian Citicen to receive an Iranian Visa at the Airport in Teheran (Tourist or maybe Transit) for a stay of Protected content , or do I have to apply for the Visa in an Iranian embassy?

As far as I am living in Turkmenistan, the idea to travel by train or by car is also a very charming one. Does somebody have any experience on this route?

Thank You for Your support

Kind regards from Ashgabat
Gerhard