TEHRAN -- A team of archaeologists has discovered ruins of the ceremonial hall of the Sassanid era Khosrow Palace near the city of Qasr-e Shirin in the western Iranian province of Kermanshah, the Persian service of CHN reported on Friday.

The hall was constructed of cobblestone and gypsum and measures 12.5x26 meters.

“Studies indicate that the hall had a large arch built of bricks of different sizes overhead,” team director Yusef Moradi said.

The hall is surrounded by a number of porticos with stone and brick columns, and the team recently discovered frescos on the columns, he added.

Covering an area of 75,000 square meters, the palace was built by the Sassanid king Khosrow II for his Armenian Christian wife Shirin. Some Iranian and Arab geographers and historians of the early Islamic era called the palace one of the wonders of the world.

Archaeological studies are underway to determine the original appearance of Khosrow Palace.

The region was excavated by French archeologist and prehistorian Jacques de Morgan in the late nineteenth century, British archaeologist and writer Gertrude Margaret Lowthian Bell in 1910 and 1911, and then by Oscar Reuter. Each one prepared architectural plans of the Khosrow Palace, but the Iranian team believes that none of the plans are reliable.

The archaeological team working at the site recently discovered a wall surrounding the palace about 40 kilometers in length, which they believe was used as a defensive device for the palace.

Moradi said last February that the team is also searching for traces of Byzantine emperor Heraclius (ruled 610-641) at the palace.

Khosrow II (reigned 590-628) began a long war against the Byzantine Empire in 602 and by 619 had conquered almost all southwestern Asia Minor and Egypt.

Further expansion was prevented by the Byzantine emperor Heraclius, who between 622 and 627 drove the Persians back within their original borders. Many experts believe that the Khosrow Palace had been sacked and pillaged by Heraclius.