The country's true capitals were Susa, Babylon and Ecbatana.
This accounts for the fact that the Greeks were not acquainted with the city until Alexander the Great took and plundered it.
Ariobarzanes himself was killed either during the battle or during the retreat to Persepolis.
The other three sides are formed by retaining walls, which vary in height with the slope of the ground.
Rising from 5–13 metres (16–43 feet) on the west side was a double stair. To create the level terrace, depressions were filled with soil and heavy rocks, which were joined together with metal clips.
Grey limestone was the main building material used in Persepolis.
After natural rock had been leveled and the depressions filled in, the terrace was prepared.
Professor Olmstead suggested the cistern was constructed at the same time that construction of the towers began.
The uneven plan of the terrace, including the foundation, acted like a castle, whose angled walls enabled its defenders to target any section of the external front.
Major tunnels for sewage were dug underground through the rock.
A large elevated water storage tank was carved at the eastern foot of the mountain.
After several months, Alexander allowed his troops to loot Persepolis.