TEHRAN – A team of archaeologists has carved a precise drainage system behind a royal bas-relief in the UNESCO-registered Persepolis in order to protect the massive rock-carved art from absorbing moisture which accelerates its erosion.

The drainage was designed and made following an archaeological survey aimed to help protect a trilingual bas-relief, which is attributed to Darius the Great (r. 522 BC – 486 BC), ILNA reported on Sunday.

“Historical monuments are usually eroded and damaged quickly due to constant climate change, moisture absorption, and evaporation,” said Iranian archaeologist Vahid Barani, who led the survey.

Rainwater is one of the factors for the surface damage of sedimentary and calcareous rocks as it penetrates and dampens inner rock layers, the archaeologist explained.

“This moisture carriages soil minerals to the rock layers… and after evaporation of water, harmful minerals will be remaining on the rock face.”

This phenomenon causes damage and erosion of the outer surface of the stones, here the ones that bear reliefs and inscriptions, he said.

The inscription of Darius the Great was carved on a rock face measuring 8.15 meters by 2.05 meters near a southern entrance to Persepolis.

Therefore, the experts of Persepolis’s Archaeological Department focused on eliminating the harmful elements, especially moisture, and examined the possibility of creating drainage with the least possible interference.

Furthermore, the team pursued a scientific, archaeological approach to shield (and eliminate) soil that existed behind the bas-relief, Barani explained.

Persepolis, also known as Takht-e Jamshid, whose magnificent ruins rest at the foot of Kuh-e Rahmat (Mountain of Mercy), was the ceremonial capital of the Achaemenid Empire. It is situated 60 kilometers northeast of the city of Shiraz in Fars province.

The royal city of Persepolis, which ranks among the archaeological sites which have no equivalent, considering its unique architecture, urban planning, construction technology, and art, was burnt by Alexander the Great in 330 BC apparently as revenge to the Persians because it seems the Persian King Xerxes had burnt the Greek City of Athens around 150 years earlier.

The city’s immense terrace was begun about 518 BC by Darius the Great, the Achaemenid Empire’s king. On this terrace, successive kings erected a series of architecturally stunning palatial buildings, among them the massive Apadana palace and the Throne Hall (“Hundred-Column Hall”).

This 13-ha ensemble of majestic approaches, monumental stairways, throne rooms (Apadana), reception rooms, and dependencies is classified among the world’s greatest archaeological sites.

The ancient region, known as Pars (Fars), or Persis, was the heart of the Achaemenid Empire founded by Cyrus the Great and had its capital at Pasargadae. Darius I the Great moved the capital to nearby Persepolis in the late 6th or early 5th century BC. Alexander the Great defeated the Achaemenian army at Arbela in 331 and burned Persepolis apparently as revenge to the Persians because it seems the Persian King Xerxes had burnt the Greek City of Athens around 150 years earlier.

AFM