Persepolis, The centre of the great Persian Empire

The city’s remote location kept it a secret from the outside world, and it became the safest city in the Persian Empire for storing art, artifacts, archives, and keeping the royal treasury. The Greeks had no idea the city existed until it was sacked and plundered by Alexander the Great (l. 356-323 BCE) in 330 BCE, who burned it and carried off its vast treasures.