Which major accomplishment was achieved by Darius I of Persia

Darius I, also known as Darius the Great, was the third Persian King of the Achaemenid Empire. His reign served 36 years, from c. 522 to 486 BCE;

While this time the Persian Empire approached its peak. Darius led military campaigns in Europe, Greece, and even in the Indus valley, overcoming lands and growing his empire. Not only returning to military courage, but Darius also changed the legal and economic system Managed impressive construction projects across the Persian Empire.

Darius I (550-486 B. C.) was the third Persian King of the Achaemenid Empire. During his reign, the Persian Empire reached its peak. He founded Persepolis in 515 B. C. and this was his major accomplishment. It is believed that this was the capital of Persia during his reign. Persepolis had a ceremonial function since it was used to celebrate the Persian New Year and it was considered one of the greatest constructions of the ancient world. Darius' role is important because he was the one that built the palaces: there are even Inscriptions on the buildings that support the idea that they were constructed by Darius.