Imagine the lapping of the Marmara Sea onto the base of the palace ramparts, and visualize a continuous arcade of columned windows above a stepped portal flanked by twin lions allowing access to the palace by sea. These were the features of the Bucoleon Palace, the main living quarters of the Great Palace from the 9th to 11th centuries A.D., when the imperial family moved to Blachernae above the Golden Horn. The Bucoleon Palace was mostly in ruins, and whatever remained was regrettably demolished to make way for the commuter railway. All that's left today is a bleak wall of arched windows, topped by a handful of gececondus (unpermitted shanties that go up at night when no one is looking) visible from the sea-facing side of Sultanahmet just outside of the entrance to Aksakal Caddesi. Those lions, by the way, are now in the Istanbul Archaeology Museum.