Returning to Khorasān from the Hajj pilgrimage, Nāser Khosrow passed the Persian Gulf and landed in Mahroban Port, heading toward Isfahān. In this part of his travelogue, he mentions To-Wah and Kāzeroon which were located on his right side, along the road which led to south. In this report, To-Wah is Taw-Waj or Taw-Waz: a famous town or region, referred to in the documents of historical geography remaining from the first Islamic centuries. This short description is of special importance because it helps us find the geographic location of Taw-Waj. According to the most of historical geographic sources, that Taw-Waj is located in the Garmsir region of Fārs across the Shāpoor River. However, Nāser Khosrow’s Travelogue states that it is located in a mountainous area. Therefore, Nāser Khosrow, as an eye witness, offers a unique description of this place. The uniqueness of his description does not end here. His report on Ya'qub Layth which describes Mahrooban’s location is also notable, and no such report exists in other famous books such as Tarikh-e Sistan (The History of Sistān). This piece of evidence proves that Nāser Khosrow's familiarity with local areas has an important role in forming the facts and details of his Travelogue and therefore in giving it credit.
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