A different woman

There's a city, old and dark;
Famously the spectator's landmark.
There's history in its bylanes
Of chaos at a magnanimous scale.
With embroidering careful secrets,
The city survives each passing day.

And there's a river running through it
Like a cold dagger through the heart,
Turning the blood warm by the cut,
A slice of Christmas cake, little burnt.

And you thought there's a lady somewhere
Find her, if you please, on a desolate square.