Avestan geography refers to the investigation of place names in the Avesta and the attempt to connect them to real-world geographical sites. It is therefore different from the cosmogony expressed in the Avesta, where place names refer to mythical events or a cosmological order. Identifying such connections is important for localizing the people of the Avesta and is therefore crucial for understanding the early history of Zoroastrianism and the Iranian peoples. Sources for such geographical references are exclusively found in the younger Avestan portion of the text, in particular in the Vendidad and several of the Yashts. The identification of these Avestan place names with real locations is often supported by comparisons with references made in later Iranian sources. A major challenge to establish these connections is the fact that the Iranian people often used the same name for different places. As a result, not all Avestan place names can be identified with certainty with present-day locations and therefore remain subject to debate. Modern scholarship, however, agrees that the place names in the Avesta are concentrated in the eastern regions of Greater Iran up to the Indo-Iranian border. Vendidad references The main Avestan text of geographical interest is the first chapter of the Vendidad (, 'The Law repudiating the Deavas'). It consists of a list of the sixteen good lands () and countries () created by Ahura Mazda. Each country is introduced with a verse describing its Ohrmazdian characteristic, followed by one describing the corresponding counter-creation () by Angra Mainyu. The only exceptions are the first and eleventh country on the list where two verses explain its Ahrimanic counter-creation: Early Pahlavi sources have traditionally located many of these countries in the western Iranian regions; a tendency that was followed by much of 20th century scholarship. This changed with the work of Gherardo Gnoli who argued that all place names in the Vendidad are located in the eastern part of Greater Iran, i.e. centered around modern day Afghanistan and Tadjikistan. Since then, a number of revisions of Gnoli's work have been proposed, often attempting to derive the position of the more uncertain place names from an assumed arrangement according to which countries appear in the list. The following list presents these place names and discusses the different localization attempts made by scholars throughout the years: Airyanem Vaejah, by the good river Daitya (): The identity of both Airyanem Vaejah and the