Panorama 1453 puts you inside the morning Constantinople's walls were breached, a few steps from the actual Theodosian ramparts at Topkapı. The centrepiece is one circle of painting, roughly 2,350 square metres holding some ten thousand figures, and it closes overhead into a complete dome, sky included. There is no frame and no visible edge: the painted ground rolls down into real earth, with broken cartwheels and cannonballs scattered at your feet, so canvas and floor become one scene.
You stand at the centre and the horizon surrounds you completely: banners, siege towers, the smoke of the great bronze cannon, the breached rampart. Recorded drums, horns and cannon fire roll around the room, and the light is pitched like an overcast dawn. The room has staged this morning since 2009, and it does so from the besieging army's side of the wall. You stand behind the Ottoman guns; the defenders are distant figures on the rampart, already being pushed back.