Soheil Callage: The Temple of Anahita in Kangavar, Kermanshah, is believed to be from the Parthian era (200 BCE).  It was mostly destroyed in the earthquake of 1957. On this historical site you can actually touch and feel the pieces of rock columns and wonder how artistically they carved them without any machinery tools more than 2000 years ago.

Wikipedia: The Anahita Temple (Persian: معبد آناهیتا or پرستشگاه‌ آناهیتا‎) is the name of one of two archaeological sites in Iran popularly thought to have been attributed to the ancient deity Anahita. The larger and more widely known of the two is located at Kangāvar in Kermanshah Province. The other is located at Bishapur.
 
The remains at Kangavar reveal an edifice that is Hellenistic in character, and yet display Persian architectural designs. The plinth's enormous dimensions for example, which measure just over 200m on a side, and its megalithic foundations, which echo Achaemenid stone platforms, "constitute Persian elements". This is thought to be corroborated by the "two lateral stairways that ascend the massive stone platform recalling Achaemenid traditions", particularly that of the Apadana Palace at Persepolis.
 
Another Iranian construction with Hellenistic characteristics is the Khurra mausoleum in Markazi Province >>>