A year ago, the task of tormenting undergraduates in a summer journalism program in Italy often involved lancing and draining much of the local color from their stories. We were stationed in Cagli, a hill town in the Apennines, and nearly every story the students submitted opened with some reference to "the town with the quaint cobblestone streets nestled between the mountains."
It fell to me, the grim copy editor hovering over their texts, to point out that (1) when the same device opens a dozen stories, little originality is present, and (2) the streets of Cagli are not paved with cobblestones. The streets of Cagli are paved with rectangular stones.
Cobblestones are rounded stones, “larger than a pebble and smaller than a boulder” in Webster’s New World College Dictionary’s helpful citation, used to pave streets. Bouncing over them is a little like driving on cannonballs.
What careless or ill-informed writers call cobblestones are seldom that, but rather a different sort of paving stone. In Baltimore, Philadelphia and New York, the common paving stones were Belgian blocks, rough-hewn rectangles of granite, often carried as ballast in ships. They provide a durable surface, and one much less uncomfortable to navigate across than cobblestones.
Whenever you see cobblestones, ask the writer if the stones were rounded. Or just make a safe substitution of paving stones. Ditch the quaintness, too.