Taq Kasra, also called the Archway of Ctesiphon, is located about 35 kilometers (22 miles) south of Baghdad. It is the only above-ground structure that remains of Ctesiphon, an ancient city that acted as the royal capital of the Persian Empire, notably during the Parthian and Sasanian periods, until the Muslim conquest of the region in the seventh century. While there is some debate as to the year of its construction, the archway is at least 1,400 years old. It was part of the city’s palace complex, possibly the ceiling…