Algeria: Timgad’s growing grid, Ghardaïa’s flood channels and Tassili’s disputed rock-art dates

Trajan founded Thamugadi, now known as Timgad, in AD 100. By the mid-second century, the town had spread beyond its original grid, and most of the major public buildings in the newer quarters date from the Severan period. The site retains paved streets, 14 baths and house mosaics. A Byzantine fort was added south of the town in 539 using Roman masonry; habitation ended after the eighth century. The long period without new building, together with almost continual excavations from 1881 to 1960, helped keep later structures off the remains.[1]

UNESCO lists five fortified settlements with palm groves in the M’Zab valley: El-Atteuf, Bounoura, Melika, Ghardaïa and Beni-Isguen. The agency says they were founded between 1012 and 1350. Remini’s 2018 study focuses on Ghardaïa’s eastern palm grove and draws on about 15 field missions made from 2006 to 2018. It calls the floodwater Maa Essiel. The 20 m Tissanbadh dam, with 36 sliding gates, directs water toward the gardens through underground galleries. Six underground galleries were planned. Remini’s 2018 account says five were operating; the branch to Chaabet de Toundja remained unfinished after 40 years of work, with more than 40% of its route excavated. Thirty-eight shafts ventilated the galleries. Inside the grove, narrow lanes also carry water during floods. Each garden receives its share through a koua opening in its wall, about 30 cm high; its width varies with the plot’s area and the owner’s contribution. A 5 cm rafsa sill beside the opening helps raise water for entry and estimate irrigation flow. The paper says floodwater irrigation happens only once or twice a year, and that several structures have disappeared.[2][3]

UNESCO places this 72,000 km² plateau in southeast Algeria. The agency calls its eroded sandstone formations “rock forests” and puts the number of identified works above 15,000, spanning drawings and engravings. In a 2011 study, Jitka Soukopova distinguishes Round Head paintings from Bubaline engravings and later Pastoral imagery. She considers it likely that Round Head paintings date to the tenth millennium BP, but notes that researchers disagree. Proposed dates for Bubaline engravings also differ, from the tenth to the eighth millennium BP. Within the Round Head style’s animal imagery, antelope and mouflon account for 90%. Elephants, hippos and rhinoceroses are among the animals she relates to evidence of a wetter climate. She places Pastoral images of domesticated animals in the eighth to seventh millennia BP. UNESCO reads the Round Head representations as possibly reflecting “magic-religious” practices roughly 10,000 years old; later images include horses and camels being tamed.[4][5]