The palette
Two reds make this city: the red-brown sandstone of the ridge and the caves, and the brick red of the terraces below. A map has one ink for all its buildings and cannot split them by district, so choose one of the two and let the weave say the rest. Our poster takes the brick. Let the old core carry a fine dense weave with no grid to fall back on, and let the Meadows be frankly regular underneath it, so the two halves argue. Give the Trent a broad calm tone but keep it low in the frame; it borders the city, it does not run through it. Green comes in firm masses at the edges rather than scattered through.