TEHRAN – Conservation teams in the UNESCO-registered Susa have completed a project to safeguard and protect 253 architectural remains from the Achaemenid-era Apadana Palace, the head of the Susa World Heritage base said on Tuesday.

Ali Bouyeri said protective and rescue measures on the stone remains of the Apadana Palace have been an ongoing process for several decades.

“Funded by the Khuzestan Cultural Heritage, Tourism and Handicrafts Department, the project covered stone elements, including column capitals, column shafts and column bases.”

He said a French archaeological team led by Jean Perrot in the 1970s consolidated dispersed stone elements in the southern section of the palace’s eastern portico to prevent further damage and facilitate study.

Bouyeri said additional measures were taken in the 2010s to counter environmental deterioration, especially moisture. Two metal platforms with wooden surfaces were installed to hold stone fragments, he added. One temporary protective structure built during that period required redesign due to limited effectiveness during heavy rainfall.

He underlined the metal structure and pitched roof were inadequate for directing surface water and needed technical improvement for long-term conservation.

Bouyeri said a new project was launched to standardize and ensure sustained protection of the remains while preserving the visual integrity of the Apadana Palace site. The upgraded shelter, designed to match the historical environment, has now been implemented.

Situated in the lower Zagros Mountains, Susa--identified as Shushan in the Book of Esther and other Biblical texts--is one of the oldest continuously inhabited cities in the world.

Visitors entering the archaeological zone can follow marked paths past date palms toward the remains of the Palace of Darius I, built around 521 BC during the Achaemenid period. To the east lies the Royal City, an area featuring deep excavations through 15 cultural layers. South of the site stands an eroded earthen tower overlooking nearby open land.

To the west is the early-20th-century Shush Castle, constructed by French archaeologists on the remains of an ancient Elamite platform. Although the structure is closed to the public, paths around its base provide views across the archaeological complex, including the Tomb of Daniel on the southern side.

Susa is referenced repeatedly in Biblical tradition. The Book of Esther describes events said to have taken place in the city during the reign of a Persian king identified as Ahasuerus. The narrative forms the basis of the Jewish festival of Purim. The city is also mentioned in the books of Nehemiah and Daniel, which relate to the 6th-century BC period known as the Babylonian captivity. A shrine known as Shush-Daniel is traditionally associated with the prophet Daniel and is distinguished by its conical dome.

Archaeological evidence shows that Susa has been inhabited since at least 4200 BC, with indications of earlier settlement dating to around 7000 BC and pottery remains from approximately 5000 BC. Objects uncovered at the site include carved cylinder seals, jewelry, clay artifacts, and cuneiform tablets containing administrative, commercial, and mathematical records.

In 330 BC, Susa was captured by Alexander of Macedon, after which the city became part of the Seleucid Empire and was known as Seleucia on the Eulaeus. A Greek-style palace was constructed near the earlier Achaemenid complex, and inscriptions from the period have been found primarily in the southern part of the city. During the Parthian era, Susa served as a minting center.

In the Sasanian period, the city had a significant Christian community. It was damaged during the reign of Shapur II, who relocated part of the population, though Susa later recovered sufficiently to resist Arab forces in the 7th century before eventually being incorporated into the early Islamic realm. The settlement remained an important regional center until the 13th century CE.

According to UNESCO, Susa contains the remains of administrative, residential, and palatial structures, with archaeological layers spanning from the 5th millennium BC to the 13th century CE.

AM