[German version] (Ἀθύρας;
Athýras). Small river, which flows into the Propontis west of Byzantium, today Kara-su (Plin. HN 4,47; according to Ptol. 3,11,4 several branches). In the late Roman era, the fortified harbour settlement (Amm. Marc. 22,8,8) was restored by Justinian (Procop. Aed. 4,8,18). The fortified stone bridge, which was destroyed by Krum in 812, was famous. von Bredow, Iris (Bietigheim-Bissingen) Bibliography V. Zlatarski, Istorija na bălgarskata dăržava prez srednite vekove 1,1, 21994, 275.