the name Raqqa rather than the official Abbasid name of al-Rafiqah. The writer Ibn al-Sam'ani also recorded this shift over a century later. During Raqqa's rapid growth in the late 20th century, al-Rafiqah was almost completely built over with new construction, and today almost nothing remains of the Abbasid city. Still, about of the original -long city walls remain today, indicating the massive scale of al-Rafiqah's fortifications. The 6.20m-thick walls themselves consisted of mud brick on a stone foundation, and their exterior was further reinforced by a stabilized burnt-brick cladding. The walls had 132 towers. Like the Abbasid capital of Baghdad, al-Rafiqah was protected by a series of outer defenses, which together made up a triple line of defense that any attackers would have to get through. A second, outer wall, itself 4.5m thick, was built beyond the first wall (at a distance of 20.8m). Beyond that, there was a 15.9m-wide moat. Both the outer wall and the moat were bulldozed in the 1970s or 80s to make room for new construction. Although al-Rafiqah covered a much smaller area than the round city of Baghdad (less than half), it was much more heavily fortified because of its location close to the Byzantine frontier. The walls of al-Rafiqah were built a meter thicker than Baghdad's, and it had more (and larger) defensive towers. The north gate of al-Rafiqah, excavated and partly rebuilt in the 1990s, is the earliest surviving city gate from the Abbasid period. Its name was probably the Bāb Ḥarrān, or the Harran Gate. Its basic layout is "a tower gate with a rectangular room and a deep entrance niche". The structure is tall, with a ramp on the west side leading up to the top. The gateway was built from stone up to a height of about 2m (above that it was built from brick), while the door opening itself measures 4m. Archaeologists found two door posts made out of solid iron still standing in place here. These probably represent the last traces of a pair of massive iron doors, like the ones that historical texts often mention as part of the entryways to early Islamic cities and palaces. For Raqqa in particular, although not necessarily the Bab Harran itself, different traditions mention an iron gate that originally was part of the Byzantine city of Amorion before being carried off to Samarra in 838 after the Abbasids captured