Hieron (Yoros) Castle is located on the Asian side of the Bosphorus. It was perhaps built by Manuel I Komenos, with Geonese rebuilding. It was taken by the Genoese in 1350 and by Mehmet II in 1452.
Entrance to the Black Sea by W.H. Bartlett (1838)
Junction of the Bosporus and Black Sea by Edward Daniel Clarke (1810)
Bildlexikon zur Topographie Istanbuls: Byzantion, Konstantinupolis, Istanbul by Wolfgang Müller-Wiener
Oxford Dictionary of Byzantium edited by Alexander Kazhdan