Set the royal buildings on a raised terrace; climb it by broad double stairs with very low, deep steps, and line their parapets with reliefs of the procession that climbs them.
steps of the Great Stairway ≈ 10 cm high
Build where none has built before
Raise the royal seat on a new terrace cut from the mountain and built out over the plain, walled as a fortress, and make it secure, beautiful and fitting.
Darius began Persepolis around 518 BC on a site that had no earlier city: a terrace about 450 by 300 m, partly cut from the rock of the Mountain of Mercy and partly built up with great blocks, standing 8 to 14 m above the plain. His inscription on its south face says that where no fortress had been built, he built one. A mud-brick wall with towers ran along the edge of the terrace and up the mountain behind it.
Related rules
Wall the royal garden, water it by channels, and plant its trees at equal distances in straight rows, so that every line and angle is regular.
Cite this page Chris Paton, “Build where none has built before”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/darius-fortress-terrace. Text, drawings and models licensed under CC BY-NC 4.0.