Conurbation (noun)
conurbation [kon-er-bey-shuh n]

noun
1. an extensive urban area resulting from the expansion of several cities or towns so that they coalesce but usually retain their separate identities.

Origin: 1910-15; con- + Latin urb- (stem of urbs) city + -ation

Now YOU come up with a sentence (or fic? or graphic?) that best illustrates the word.