Herat dates back to very old times. Avesta, the old book of Zoroastrianism mentions Herat as "Haroyu" and lists it as the sixth land of the sixteen perfect lands created by Ahura Mazda, the Zoroastrian god. In Achaemenid times (ca. 550-330 BC), the surrounding district was known as "Haraiva" (in Old Persian). Ancient Greeks called it "Aria" and "Artacoana" was the capital of Aria. Alexander the Great took Artacoana in 330 BC and destroyed it. He later built another city near Artacoana and named it "Alexandria in Ariana", today's city of Herat. After him Parthians and Sassanians took over. Sassanians called the city “Harēv”.