Answer:
Large cities tend to be nucleated settlements instead of linear or dispersed settlements, because large cities usually grow from a small core that expands over time, often in a radial direction, that is to say, on all sides.
A typical example of a nuclear large city is Paris. Paris grew from two small islands on the Seine River and their immediate sorroundings, to a large metropolis that extends several miles inland from this starting point, in a more or less circular shape, with the original core being the nucleus of the urban area.