The township of Sar Pol-e-Zahab is located in the west of the province and is limited to Iraq from its western borders. Its climate is warm but in some parts temperate. This city is located at the distance of 665 km. from Tehran. Sar Pol-e-Zahab is near the ruins of the ancient city of Halvan and a ruined castle can be also seen near the same. Sar Pol-e-Zahab was considered as a castle and frontier base of Iran, which was destroyed in the Arab invasion to Iran, and only some remnants of its brick laid pillars have remained. In historical books it has been mentioned as the center of Halvan state.
The name of "Sar Pol" has been taken from a bridge on Alvandoo River and the suffix of "Zahab" was due to the abundance of springs and wetlands. This city with its natural attractions sustained losses in the imposed war but after the conclusion of the war it was renovated.