complexes dating to the period have been excavated by a German team on behalf of the Director General of Antiquities. There was also a thriving industrial complex located between the twin cities. Both German and English teams have excavated parts of the industrial complex, revealing comprehensive evidence for pottery and glass production. Apart from large dumps of debris, the evidence consisted of pottery and glass workshops, containing the remains of pottery kilns and glass furnaces. Approximately west of Raqqa lay the unfinished victory monument Heraqla from the time of Harun al-Rashid. It is said to commemorate the conquest of the Byzantine city of Herakleia in Asia Minor in 806. Other theories connect it with cosmological events. The monument is preserved in a substructure of a square building in the centre of a circular walled enclosure, in diameter. However, the upper part was never finished because of the sudden death of Harun al-Rashid in Greater Khorasan. Harun al-Rashid also invested in the water supply in Raqqa. Under his rule, canals were dug along the Euphrates and Balikh rivers; they brought water from the area around Saruj to be used for domestic and agricultural purposes, as well as to supply the palace gardens with water. Meanwhile, the influx of residents generated plenty of demand for food, goods, and services, stimulating the economy and resulting in intensified activity in Raqqa's rural hinterland. Rural towns such as Hisn Maslama, Tall Mahra, and al-Jarud flourished and reached their peak size. The surrounding countryside at this time was "one of the richest agricultural areas of the empire, with an extensive system of irrigation canals". After the return of the court to Baghdad in 809, Raqqa remained the capital of the western part of the Abbasid Caliphate. Geography of Abbasid Raqqa The name "Raqqa" was used both for the entire urban sprawl, or more specifically for the old city of Raqqa aka Kallinikos. The old city was also known by the name al-Raqqah al-Bayḍā'. It had "almost rectangular" walls, although their entire extent is not known. Where the gates were located is also unknown. This area had a predominantly indigenous population. Al-Rafiqah Somewhat to the west of Raqqa proper was al-Rāfiqah, which had horseshoe-shaped walls. Al-Rafiqah represents the location of present-day Raqqa; at some point the main center shifted here. The earliest evidence for this shift is a Fatimid dinar minted at Raqqa in 1010-11, which uses