Persepolis was constructed 2,500 years ago as the jewel in the crown of the vast Achaemenid realm – one of the largest empires the world has ever seen. Darius the Great began the construction of the city in about BC518 and it functioned primarily as a royal residence and a showcase for the Empire's immense wealth. Today, the substantial remains of several palatial buildings lie scattered across a vast stone terrace raised several meters above the plain below. It is clear that Persepolis clearly rivalled the best of Roman and Greek cities, most of which were built substantially later. Indeed, it would not be inappropriate to compare the accomplishments here to those of the Parthenon (contemporary), the Colosseum in Rome (built 450 years later), Angkor Wat (1400 years later), Machu Picchu (1800 years later) or the Taj Mahal (2000 years later). A few kilometres from Persepolis is Naqsh-e Rostam where the magnificent tombs of Darius the Great, Xerxes, Artaxerxes I and Darius II are hewn out of a cliff face above the plain. Beneath the Achaemenid tombs are eight wonderful Sassanian bas reliefs from the third and fourth centuries AD showing scenes of Sassanian rulers’ conquests over their enemies – particularly the Romans – and portrayals of royal ceremonies. Further up the Esfahan road is Pasargadae built as a royal city in BC546 by the founder of the Achaemenid dynasty, Cyrus the Great. Rapidly eclipsed by Darius’s Persepolis the site is nothing like as well preserved, only a few fragments remaining above ground, but it is beguiling in an abandoned sort of way. The most complete structure is the massive six-tiered Tomb of Cyrus that rises above the plain conveying an impression of dignity, simplicity, and strength.