Iron Age (Yaz I period, c. 1500-1000 BC) continuing until pre-Achaemenid times (Yaz II period, c. 1000-540 BC). Bala Hissar is located at the north of the site and is oval in shape, having an area of around 1,500 by 1,000 m2 (c. 150 hectares) and to the south is the lower town. Another mound of the site, known as Tepe Zargaran, and the Northern Fortification Wall of Balkh, were occupied at a large extension in Achaemenid times (Yaz III period, c. 540-330 BC). Since the Iranians built their first kingdom in Balkh (Bactria, Daxia, Bukhdi) some scholars believe that it was from this area that different waves of Iranians spread to north-east Iran and Seistan region, where they, in part, became today's Persians, Tajiks, Pashtuns and Baluch people of the region. The changing climate has led to desertification since antiquity, when the region was very fertile. Its foundation is mythically ascribed to Keyumars, the first king of the world in Persian legend; and it is at least certain that, at a very early date, it was the rival of Ecbatana, Nineveh and Babylon. The Arabs called it Umm Al-Bilad or Mother of Cities, on account of its antiquity. The city was traditionally a center of Zoroastrianism. For a long time the city and country was the central seat of the dualistic Zoroastrian religion, the founder of which, Zoroaster, died within the walls according to the Persian poet Firdowsi. Armenian sources state that the Arsacid Dynasty of the Parthian Empire established its capital in Balkh. There is a long-standing tradition that an ancient shrine of Anahita was to be found here, a temple so rich it invited plunder. Alexander the Great married Roxana of Bactria after killing the king of Balkh. The city was the capital of the Greco-Bactrian Kingdom and was besieged for three years by the Seleucid Empire (208–206 BC). After the demise of the Greco-Bactrian kingdom, it was ruled by Indo-Scythians, Parthians, Indo-Parthians, Kushan Empire, Indo-Sassanids, Kidarites, Hephthalite Empire and Sassanid Persians before the arrival of the Arabs. Vedic Era Balkh was part of one of the Janapadas that existed in India during the Vedic period somewhere between 1500 BCE and 600 BCE. During this time they were called the Bahlikas, and were mentioned in the Atharvaveda, Mahabharata, Ramayana, Puranas, Vartikka of Katyayana, and Brhatsamhita. Bactrian religion Bactrian documents - in the Bactrian language, written from the