The wall is about 40 kilometres in length and surrounds the Shirin Palace. It was used as a defensive device for the palace, which was built by the Sasanian King of Kings Khosrow II, Parviz (reigned 590-628 CE) for his wife Shirin, said Ali Hodzabri, the director of the archaeological team working at the site.

The palace was 285x98 meters in diameter, and constructed eight meters above the surface level.

The wall is located 17 kilometres from Shirin Palace and is near the Sasanian monuments Bân-Qaleh and Châhâr-Qâpi fire-temple.

The wall, which was constructed in the anathyrosis style (stone-cutting techniques and building with dry stone without mortar), begins at the Bâzi-Derâz heights and stretches into present-day Iraq.

No historical document or study refers to the existence of such a wall, which was discovered during the current phase of excavations that began on January 5.

The ruins near Qasr-e Shirin were excavated for the first time in 1891 and later in 1910 by British archaeologist, writer and government official, Gertrude Margaret Lowthian Bell (1868-1926).