RaqqaLocated on the left bank of the Euphrates between Aleppo ( 188 km ) and Deir al-Zor ( 105 km ) . It is an ancient city built by Alexander the great in the 4 th century B.C. In 662 the Cliph Mansur built , on the ruins of Raqqa , a new city imitating the style of Baghada which called ‘ Rafqa ‘ . Invaded by the Mongols in the 12 th century . Raqqa has few remains left from that period . Theses were built by the Caliph Harun al-Rashid in the Abbasside age . Some remains of ancient Raqqa survive today . Those built in pink tile reflect a particular style of architecture . Of the Jami’I al-Kabir ( the great mosque ) , there remains only the minaret , which was reconstructed by Nur al-Din in 1166 . Pottery and glass were famous and there is a museum in the city which contains many relics can also bee seen in museums in New York , Washington and other Western cities . Raqqa is beginning to flourish again , and to play an important economic role ( after the building of the Euphrates Dam ) in the life of Modern Syria . Al-Thawra ( Tabaqa ) This is new city that rose up out the sand . It was inaugurated by president Hafz al-Assad in 1973 . Al-Thwara , ‘ The revolution ‘ , is the capital of the area of the Euphrates dam . Here , when people talk of ” the dam ” they do not only mean the huge structure that holda back the river ( 4500 meters long , 60 metres high , 512 metres wide at the base , 41 million cubic metres of rock earth and clay ) , but they also mean the al-Assad lake ( 80 km long , with 12 billion cubic meters of water, and a hydroelectric power-station , as well as the 640.000 hectares of agricultural land now brought under cultivation ) . Gone are the fears of devastating floods . Experimental farms and agricultural colleges are pointing the way to the future . Thanks to the cooperation between Unesco and the Syrian government , monuments of the site were saved from the river flood , including Ja’bar Citadel and the tow minarets of Maskana and Abi Hurayra ; relics of this sites can now be seen in the Aleppo Museum . In the distance , on the other bank of the dam , a pink fortress appears reflected in the blue water of the lake . This is at Ja;bar , one of the Seleucid fortress reconstructed by Nur al-Din in the 12 th century . It is surrounded by tow walls with thirty-five towers of different shapes. The facades of the towers are richly decorated with ornamentations and inscriptions . The citadel which has been restored is to be turned into a tourist centre . Deir al-Zor 320 km south-east of Aleppo , Deir al-Zor is the most important urban center in the east of Syria . It is river is the Euphrates , lifeline of the region and flount of civilization throughout the gaes . With the formation of Lake l-Assad , it is now possible to regulate its once capricious flow and to make plans for new harvests . 85 km south of Deir al-Zor , on the western bank of the Euphrates , is the archaeological site of the birthplace of Seleucus , near the Arab village of Salihyeh . This was the historic town built by Seleucus Nicator , Alexander’s lieutenant , the fortified town od Doura Europos . This town was closely liked with Palmyra , serving as an important forward-line of defence against the Persians . The site did not attract significant attention until 1921 when some mural paintings were discovered in a temple ( there were sixteen temples dedicated to the various gods of Palmyra . many other discoveries followed , notably frescoes dating from 235 A.D . which were in a remarkable state of preservation . They , too , were transported to the Damascus Museum in 1936 . Doura Europos , however , is still a place of interest for visitors . 120 km south of this town is the site of the kingdom of Mari ( Tel Hariri ) , near abu Kamal . This kingdom dates back to the 3 rd millennium B.C . It was ruled by kings of the 19 th dynasty after the flood . The discovery of Mari (1932 ) , like the recent discovery of Ebla ( 1975 ) , attracted the attention of archaeologists and researchers in various fields . Twenty thousand tablets with their cuneiform inscription recount the political and diplomatic life in these kingdoms . Many of the remains and relics statues , jewels , tablets and stamps , are now at the Damascus , Aleppo , Deir al-Zor and paris museums . Another archeological site is at the intersection of the Euphrates and of the Khabour near Mavadin ( Tel al-Ashara ) , where are ancient city of Tarqa , the capital of Khana kingdom , flourished in the 2 nd millennium B.C . after the fall of Mari . The wall enormous of the ancient world ; it had a diameter of 20 m . Halabiya and Zalabia North-east of Deir al-zor , there is a vast enclosing wall with three fortified gateways which enfolds within its towers a town that dates from Byzantine days . Both Halabiya and Zalabiya were forward-defence lines against Presianst invasions . At Mayadin is the Rahbi Citadel , which was built by Assad al-Din Shirgoh , the uncle of Salah al-Din al-Ayoubi .