Iran: An Islamic Experiment from BBC News.
The Median capital at Hamadan, from 7th century BC, Iran, 1976
According to Herodotus, Hamadan - the ancient Persian Hagmatana, Greek Ecbatana - was built by the first king of the Medes, Deioces, as a residence and as the first city of the Medes. Herodotus's description of seven concentric walls, each a different colour and slightly higher than its neighbour, is entirely fanciful. Situated on the main road to Mesopotamia at a height of almost 2000m, with a good climate, plentiful supply of water and on a large fertile plain, this was the most important city on the plateau during the Achaemenid period. Alexander the Great hoped to turn it into the capital of the eastern Empire.
Picture, caption, and quote from The Past from Above (amazon.com link)