Explain the Main Features of Darius 1 Reign

In 521 BC Susa was made Darius's administrative capital, he restored fortifications as well as building a residential palace and an audience hall. On the palace there are inscriptions which describe how it was a work of all over the empire, making it a multicultural work.
In Persia Darius founded a new royal capital called Persepolis to replace Pasargadae. At Persepolis he is attributed to the fortifications, apadana, council hall, treasury, and a residential palace are, although not completed in his lifetime. As well as this he also had various building programs at Ecbana and Babylon. We have remains at all the major sites that Darius built at.
Another feature of Darius's building program was the royal road.…