| Poshtab Castle | |
| Native Name: | قلعه پشتاب |
| Location: | Ahar County |
| Nearest Town: | Poshtab village |
| Country: | Iran |
| Type: | Castle |
Poshtab Castle, also known Pashtou Castle (Persian: قلعه پشتاب) is an ancient site in Poshtab village, Ahar County in north-west of Iran. Poshtab Castle is built on a rock in which there is stairs and engraved cabins. There is only one way to enter to castle and other sides face to inaccessible dangerous cliffs around itself. The Building dates back Sassanid and Parthian empire. Poshtab Fortification is located near Qahqaheh Castle.